Merge branch 'main' into glitch-soc/merge-upstream

Conflicts:
- `README.md`:
  Upstream updated copyright year, we don't mention it so kept our version.
- `app/controllers/admin/dashboard_controller.rb`:
  Not really a conflict, upstream change (removing the spam checker) too close
  to glitch-soc changes. Ported upstream changes.
- `app/models/form/admin_settings.rb`:
  Same.
- `app/services/remove_status_service.rb`:
  Same.
- `app/views/admin/settings/edit.html.haml`:
  Same.
- `config/settings.yml`:
  Same.
- `config/environments/production.rb`:
  Not a real conflict, upstream added a default HTTP header, but we have
  extra headers in glitch-soc.
  Added the header.

59 files changed, 1040 insertions, 444 deletions

diff --git a/app/controllers/admin/dashboard_controller.rb b/app/controllers/admin/dashboard_controller.rb
index 9e921fb95..a00d7ed96 100644
--- a/app/controllers/admin/dashboard_controller.rb
+++ b/app/controllers/admin/dashboard_controller.rb
@@ -36,7 +36,6 @@ module Admin
       @profile_directory     = Setting.profile_directory
       @timeline_preview      = Setting.timeline_preview
       @keybase_integration   = Setting.enable_keybase
-      @spam_check_enabled    = Setting.spam_check_enabled
       @trends_enabled        = Setting.trends
     end
 
diff --git a/app/controllers/admin/follow_recommendations_controller.rb b/app/controllers/admin/follow_recommendations_controller.rb
new file mode 100644
index 000000000..e3eac62b3
--- /dev/null
+++ b/app/controllers/admin/follow_recommendations_controller.rb
@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+module Admin
+  class FollowRecommendationsController < BaseController
+    before_action :set_language
+
+    def show
+      authorize :follow_recommendation, :show?
+
+      @form     = Form::AccountBatch.new
+      @accounts = filtered_follow_recommendations
+    end
+
+    def update
+      @form = Form::AccountBatch.new(form_account_batch_params.merge(current_account: current_account, action: action_from_button))
+      @form.save
+    rescue ActionController::ParameterMissing
+      # Do nothing
+    ensure
+      redirect_to admin_follow_recommendations_path(filter_params)
+    end
+
+    private
+
+    def set_language
+      @language = follow_recommendation_filter.language
+    end
+
+    def filtered_follow_recommendations
+      follow_recommendation_filter.results
+    end
+
+    def follow_recommendation_filter
+      @follow_recommendation_filter ||= FollowRecommendationFilter.new(filter_params)
+    end
+
+    def form_account_batch_params
+      params.require(:form_account_batch).permit(:action, account_ids: [])
+    end
+
+    def filter_params
+      params.slice(*FollowRecommendationFilter::KEYS).permit(*FollowRecommendationFilter::KEYS)
+    end
+
+    def action_from_button
+      if params[:suppress]
+        'suppress_follow_recommendation'
+      elsif params[:unsuppress]
+        'unsuppress_follow_recommendation'
+      end
+    end
+  end
+end
diff --git a/app/controllers/api/v1/push/subscriptions_controller.rb b/app/controllers/api/v1/push/subscriptions_controller.rb
index 0918c61e9..47f2e6440 100644
--- a/app/controllers/api/v1/push/subscriptions_controller.rb
+++ b/app/controllers/api/v1/push/subscriptions_controller.rb
@@ -3,13 +3,13 @@
 class Api::V1::Push::SubscriptionsController < Api::BaseController
   before_action -> { doorkeeper_authorize! :push }
   before_action :require_user!
-  before_action :set_web_push_subscription
-  before_action :check_web_push_subscription, only: [:show, :update]
+  before_action :set_push_subscription
+  before_action :check_push_subscription, only: [:show, :update]
 
   def create
-    @web_subscription&.destroy!
+    @push_subscription&.destroy!
 
-    @web_subscription = ::Web::PushSubscription.create!(
+    @push_subscription = Web::PushSubscription.create!(
       endpoint: subscription_params[:endpoint],
       key_p256dh: subscription_params[:keys][:p256dh],
       key_auth: subscription_params[:keys][:auth],
@@ -18,31 +18,31 @@ class Api::V1::Push::SubscriptionsController < Api::BaseController
       access_token_id: doorkeeper_token.id
     )
 
-    render json: @web_subscription, serializer: REST::WebPushSubscriptionSerializer
+    render json: @push_subscription, serializer: REST::WebPushSubscriptionSerializer
   end
 
   def show
-    render json: @web_subscription, serializer: REST::WebPushSubscriptionSerializer
+    render json: @push_subscription, serializer: REST::WebPushSubscriptionSerializer
   end
 
   def update
-    @web_subscription.update!(data: data_params)
-    render json: @web_subscription, serializer: REST::WebPushSubscriptionSerializer
+    @push_subscription.update!(data: data_params)
+    render json: @push_subscription, serializer: REST::WebPushSubscriptionSerializer
   end
 
   def destroy
-    @web_subscription&.destroy!
+    @push_subscription&.destroy!
     render_empty
   end
 
   private
 
-  def set_web_push_subscription
-    @web_subscription = ::Web::PushSubscription.find_by(access_token_id: doorkeeper_token.id)
+  def set_push_subscription
+    @push_subscription = Web::PushSubscription.find_by(access_token_id: doorkeeper_token.id)
   end
 
-  def check_web_push_subscription
-    not_found if @web_subscription.nil?
+  def check_push_subscription
+    not_found if @push_subscription.nil?
   end
 
   def subscription_params
@@ -52,6 +52,6 @@ class Api::V1::Push::SubscriptionsController < Api::BaseController
   def data_params
     return {} if params[:data].blank?
 
-    params.require(:data).permit(alerts: [:follow, :follow_request, :favourite, :reblog, :mention, :poll, :status])
+    params.require(:data).permit(:policy, alerts: [:follow, :follow_request, :favourite, :reblog, :mention, :poll, :status])
   end
 end
diff --git a/app/controllers/api/v1/suggestions_controller.rb b/app/controllers/api/v1/suggestions_controller.rb
index 52054160d..b2788cc76 100644
--- a/app/controllers/api/v1/suggestions_controller.rb
+++ b/app/controllers/api/v1/suggestions_controller.rb
@@ -19,6 +19,6 @@ class Api::V1::SuggestionsController < Api::BaseController
   private
 
   def set_accounts
-    @accounts = PotentialFriendshipTracker.get(current_account.id, limit: limit_param(DEFAULT_ACCOUNTS_LIMIT))
+    @accounts = PotentialFriendshipTracker.get(current_account, limit_param(DEFAULT_ACCOUNTS_LIMIT))
   end
 end
diff --git a/app/controllers/api/v2/suggestions_controller.rb b/app/controllers/api/v2/suggestions_controller.rb
new file mode 100644
index 000000000..35eb276c0
--- /dev/null
+++ b/app/controllers/api/v2/suggestions_controller.rb
@@ -0,0 +1,19 @@
+# frozen_string_literal: true
+
+class Api::V2::SuggestionsController < Api::BaseController
+  include Authorization
+
+  before_action -> { doorkeeper_authorize! :read }
+  before_action :require_user!
+  before_action :set_suggestions
+
+  def index
+    render json: @suggestions, each_serializer: REST::SuggestionSerializer
+  end
+
+  private
+
+  def set_suggestions
+    @suggestions = AccountSuggestions.get(current_account, limit_param(DEFAULT_ACCOUNTS_LIMIT))
+  end
+end
diff --git a/app/controllers/api/web/push_subscriptions_controller.rb b/app/controllers/api/web/push_subscriptions_controller.rb
index 1dce3e70f..bed57fc54 100644
--- a/app/controllers/api/web/push_subscriptions_controller.rb
+++ b/app/controllers/api/web/push_subscriptions_controller.rb
@@ -2,6 +2,7 @@
 
 class Api::Web::PushSubscriptionsController < Api::Web::BaseController
   before_action :require_user!
+  before_action :set_push_subscription, only: :update
 
   def create
     active_session = current_session
@@ -15,9 +16,11 @@ class Api::Web::PushSubscriptionsController < Api::Web::BaseController
     alerts_enabled = active_session.detection.device.mobile? || active_session.detection.device.tablet?
 
     data = {
+      policy: 'all',
+
       alerts: {
         follow: alerts_enabled,
-        follow_request: false,
+        follow_request: alerts_enabled,
         favourite: alerts_enabled,
         reblog: alerts_enabled,
         mention: alerts_enabled,
@@ -28,7 +31,7 @@ class Api::Web::PushSubscriptionsController < Api::Web::BaseController
 
     data.deep_merge!(data_params) if params[:data]
 
-    web_subscription = ::Web::PushSubscription.create!(
+    push_subscription = ::Web::PushSubscription.create!(
       endpoint: subscription_params[:endpoint],
       key_p256dh: subscription_params[:keys][:p256dh],
       key_auth: subscription_params[:keys][:auth],
@@ -37,27 +40,27 @@ class Api::Web::PushSubscriptionsController < Api::Web::BaseController
       access_token_id: active_session.access_token_id
     )
 
-    active_session.update!(web_push_subscription: web_subscription)
+    active_session.update!(web_push_subscription: push_subscription)
 
-    render json: web_subscription, serializer: REST::WebPushSubscriptionSerializer
+    render json: push_subscription, serializer: REST::WebPushSubscriptionSerializer
   end
 
   def update
-    params.require([:id])
-
-    web_subscription = ::Web::PushSubscription.find(params[:id])
-    web_subscription.update!(data: data_params)
-
-    render json: web_subscription, serializer: REST::WebPushSubscriptionSerializer
+    @push_subscription.update!(data: data_params)
+    render json: @push_subscription, serializer: REST::WebPushSubscriptionSerializer
   end
 
   private
 
+  def set_push_subscription
+    @push_subscription = ::Web::PushSubscription.find(params[:id])
+  end
+
   def subscription_params
     @subscription_params ||= params.require(:subscription).permit(:endpoint, keys: [:auth, :p256dh])
   end
 
   def data_params
-    @data_params ||= params.require(:data).permit(alerts: [:follow, :follow_request, :favourite, :reblog, :mention, :poll, :status])
+    @data_params ||= params.require(:data).permit(:policy, alerts: [:follow, :follow_request, :favourite, :reblog, :mention, :poll, :status])
   end
 end
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 5a9496bd4..9be3419b0 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -91,8 +91,6 @@ module ApplicationHelper
       fa_icon('unlock', title: I18n.t('statuses.visibilities.unlisted'))
     elsif status.private_visibility? || status.limited_visibility?
       fa_icon('lock', title: I18n.t('statuses.visibilities.private'))
-    elsif status.direct_visibility?
-      fa_icon('envelope', title: I18n.t('statuses.visibilities.direct'))
     end
   end
 
diff --git a/app/helpers/email_helper.rb b/app/helpers/email_helper.rb
new file mode 100644
index 000000000..360783c62
--- /dev/null
+++ b/app/helpers/email_helper.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+module EmailHelper
+  def self.included(base)
+    base.extend(self)
+  end
+
+  def email_to_canonical_email(str)
+    username, domain = str.downcase.split('@', 2)
+    username, = username.gsub('.', '').split('+', 2)
+
+    "#{username}@#{domain}"
+  end
+
+  def email_to_canonical_email_hash(str)
+    Digest::SHA2.new(256).hexdigest(email_to_canonical_email(str))
+  end
+end
diff --git a/app/javascript/mastodon/actions/importer/normalizer.js b/app/javascript/mastodon/actions/importer/normalizer.js
index dca44917a..087f26491 100644
--- a/app/javascript/mastodon/actions/importer/normalizer.js
+++ b/app/javascript/mastodon/actions/importer/normalizer.js
@@ -24,6 +24,7 @@ export function normalizeAccount(account) {
 
   account.display_name_html = emojify(escapeTextContentForBrowser(displayName), emojiMap);
   account.note_emojified = emojify(account.note, emojiMap);
+  account.note_plain = unescapeHTML(account.note);
 
   if (account.fields) {
     account.fields = account.fields.map(pair => ({
diff --git a/app/javascript/mastodon/actions/onboarding.js b/app/javascript/mastodon/actions/onboarding.js
index 42d8ea33f..a1dd3a731 100644
--- a/app/javascript/mastodon/actions/onboarding.js
+++ b/app/javascript/mastodon/actions/onboarding.js
@@ -1,21 +1,8 @@
 import { changeSetting, saveSettings } from './settings';
-import { requestBrowserPermission } from './notifications';
 
 export const INTRODUCTION_VERSION = 20181216044202;
 
 export const closeOnboarding = () => dispatch => {
   dispatch(changeSetting(['introductionVersion'], INTRODUCTION_VERSION));
   dispatch(saveSettings());
-
-  dispatch(requestBrowserPermission((permission) => {
-    if (permission === 'granted') {
-      dispatch(changeSetting(['notifications', 'alerts', 'follow'], true));
-      dispatch(changeSetting(['notifications', 'alerts', 'favourite'], true));
-      dispatch(changeSetting(['notifications', 'alerts', 'reblog'], true));
-      dispatch(changeSetting(['notifications', 'alerts', 'mention'], true));
-      dispatch(changeSetting(['notifications', 'alerts', 'poll'], true));
-      dispatch(changeSetting(['notifications', 'alerts', 'status'], true));
-      dispatch(saveSettings());
-    }
-  }));
 };
diff --git a/app/javascript/mastodon/actions/suggestions.js b/app/javascript/mastodon/actions/suggestions.js
index b15bd916b..e3a549759 100644
--- a/app/javascript/mastodon/actions/suggestions.js
+++ b/app/javascript/mastodon/actions/suggestions.js
@@ -1,5 +1,6 @@
 import api from '../api';
 import { importFetchedAccounts } from './importer';
+import { fetchRelationships } from './accounts';
 
 export const SUGGESTIONS_FETCH_REQUEST = 'SUGGESTIONS_FETCH_REQUEST';
 export const SUGGESTIONS_FETCH_SUCCESS = 'SUGGESTIONS_FETCH_SUCCESS';
@@ -7,13 +8,17 @@ export const SUGGESTIONS_FETCH_FAIL    = 'SUGGESTIONS_FETCH_FAIL';
 
 export const SUGGESTIONS_DISMISS = 'SUGGESTIONS_DISMISS';
 
-export function fetchSuggestions() {
+export function fetchSuggestions(withRelationships = false) {
   return (dispatch, getState) => {
     dispatch(fetchSuggestionsRequest());
 
-    api(getState).get('/api/v1/suggestions').then(response => {
-      dispatch(importFetchedAccounts(response.data));
+    api(getState).get('/api/v2/suggestions').then(response => {
+      dispatch(importFetchedAccounts(response.data.map(x => x.account)));
       dispatch(fetchSuggestionsSuccess(response.data));
+
+      if (withRelationships) {
+        dispatch(fetchRelationships(response.data.map(item => item.account.id)));
+      }
     }).catch(error => dispatch(fetchSuggestionsFail(error)));
   };
 };
@@ -25,10 +30,10 @@ export function fetchSuggestionsRequest() {
   };
 };
 
-export function fetchSuggestionsSuccess(accounts) {
+export function fetchSuggestionsSuccess(suggestions) {
   return {
     type: SUGGESTIONS_FETCH_SUCCESS,
-    accounts,
+    suggestions,
     skipLoading: true,
   };
 };
@@ -48,5 +53,12 @@ export const dismissSuggestion = accountId => (dispatch, getState) => {
     id: accountId,
   });
 
-  api(getState).delete(`/api/v1/suggestions/${accountId}`);
+  api(getState).delete(`/api/v1/suggestions/${accountId}`).then(() => {
+    dispatch(fetchSuggestionsRequest());
+
+    api(getState).get('/api/v2/suggestions').then(response => {
+      dispatch(importFetchedAccounts(response.data.map(x => x.account)));
+      dispatch(fetchSuggestionsSuccess(response.data));
+    }).catch(error => dispatch(fetchSuggestionsFail(error)));
+  }).catch(() => {});
 };
diff --git a/app/javascript/mastodon/components/account.js b/app/javascript/mastodon/components/account.js
index 0e40ee1d6..a85d683a7 100644
--- a/app/javascript/mastodon/components/account.js
+++ b/app/javascript/mastodon/components/account.js
@@ -78,8 +78,10 @@ class Account extends ImmutablePureComponent {
 
     let buttons;
 
-    if (onActionClick && actionIcon) {
-      buttons = <IconButton icon={actionIcon} title={actionTitle} onClick={this.handleAction} />;
+    if (actionIcon) {
+      if (onActionClick) {
+        buttons = <IconButton icon={actionIcon} title={actionTitle} onClick={this.handleAction} />;
+      }
     } else if (account.get('id') !== me && account.get('relationship', null) !== null) {
       const following = account.getIn(['relationship', 'following']);
       const requested = account.getIn(['relationship', 'requested']);
diff --git a/app/javascript/mastodon/components/logo.js b/app/javascript/mastodon/components/logo.js
new file mode 100644
index 000000000..d1c7f08a9
--- /dev/null
+++ b/app/javascript/mastodon/components/logo.js
@@ -0,0 +1,9 @@
+import React from 'react';
+
+const Logo = () => (
+  <svg viewBox='0 0 216.4144 232.00976' className='logo'>
+    <use xlinkHref='#mastodon-svg-logo' />
+  </svg>
+);
+
+export default Logo;
diff --git a/app/javascript/mastodon/containers/mastodon.js b/app/javascript/mastodon/containers/mastodon.js
index 3ac58cf7c..513b59908 100644
--- a/app/javascript/mastodon/containers/mastodon.js
+++ b/app/javascript/mastodon/containers/mastodon.js
@@ -1,12 +1,10 @@
 import React from 'react';
-import { Provider, connect } from 'react-redux';
+import { Provider } from 'react-redux';
 import PropTypes from 'prop-types';
 import configureStore from '../store/configureStore';
-import { INTRODUCTION_VERSION } from '../actions/onboarding';
 import { BrowserRouter, Route } from 'react-router-dom';
 import { ScrollContext } from 'react-router-scroll-4';
 import UI from '../features/ui';
-import Introduction from '../features/introduction';
 import { fetchCustomEmojis } from '../actions/custom_emojis';
 import { hydrateStore } from '../actions/store';
 import { connectUserStream } from '../actions/streaming';
@@ -26,39 +24,6 @@ const hydrateAction = hydrateStore(initialState);
 store.dispatch(hydrateAction);
 store.dispatch(fetchCustomEmojis());
 
-const mapStateToProps = state => ({
-  showIntroduction: state.getIn(['settings', 'introductionVersion'], 0) < INTRODUCTION_VERSION,
-});
-
-@connect(mapStateToProps)
-class MastodonMount extends React.PureComponent {
-
-  static propTypes = {
-    showIntroduction: PropTypes.bool,
-  };
-
-  shouldUpdateScroll (_, { location }) {
-    return location.state !== previewMediaState && location.state !== previewVideoState;
-  }
-
-  render () {
-    const { showIntroduction } = this.props;
-
-    if (showIntroduction) {
-      return <Introduction />;
-    }
-
-    return (
-      <BrowserRouter basename='/web'>
-        <ScrollContext shouldUpdateScroll={this.shouldUpdateScroll}>
-          <Route path='/' component={UI} />
-        </ScrollContext>
-      </BrowserRouter>
-    );
-  }
-
-}
-
 export default class Mastodon extends React.PureComponent {
 
   static propTypes = {
@@ -76,6 +41,10 @@ export default class Mastodon extends React.PureComponent {
     }
   }
 
+  shouldUpdateScroll (_, { location }) {
+    return location.state !== previewMediaState && location.state !== previewVideoState;
+  }
+
   render () {
     const { locale } = this.props;
 
@@ -83,7 +52,11 @@ export default class Mastodon extends React.PureComponent {
       <IntlProvider locale={locale} messages={messages}>
         <Provider store={store}>
           <ErrorBoundary>
-            <MastodonMount />
+            <BrowserRouter basename='/web'>
+              <ScrollContext shouldUpdateScroll={this.shouldUpdateScroll}>
+                <Route path='/' component={UI} />
+              </ScrollContext>
+            </BrowserRouter>
           </ErrorBoundary>
         </Provider>
       </IntlProvider>
diff --git a/app/javascript/mastodon/features/compose/components/search_results.js b/app/javascript/mastodon/features/compose/components/search_results.js
index 4b4cdff74..a8b31b677 100644
--- a/app/javascript/mastodon/features/compose/components/search_results.js
+++ b/app/javascript/mastodon/features/compose/components/search_results.js
@@ -51,12 +51,12 @@ class SearchResults extends ImmutablePureComponent {
               <FormattedMessage id='suggestions.header' defaultMessage='You might be interested in…' />
             </div>
 
-            {suggestions && suggestions.map(accountId => (
+            {suggestions && suggestions.map(suggestion => (
               <AccountContainer
-                key={accountId}
-                id={accountId}
-                actionIcon='times'
-                actionTitle={intl.formatMessage(messages.dismissSuggestion)}
+                key={suggestion.get('account')}
+                id={suggestion.get('account')}
+                actionIcon={suggestion.get('source') === 'past_interaction' ? 'times' : null}
+                actionTitle={suggestion.get('source') === 'past_interaction' ? intl.formatMessage(messages.dismissSuggestion) : null}
                 onActionClick={dismissSuggestion}
               />
             ))}
diff --git a/app/javascript/mastodon/features/emoji/emoji.js b/app/javascript/mastodon/features/emoji/emoji.js
index 3de79ac9b..fb1a3804c 100644
--- a/app/javascript/mastodon/features/emoji/emoji.js
+++ b/app/javascript/mastodon/features/emoji/emoji.js
@@ -11,7 +11,7 @@ const emojiFilenames = (emojis) => {
 };
 
 // Emoji requiring extra borders depending on theme
-const darkEmoji = emojiFilenames(['🎱', '🐜', '⚫', '🖤', '⬛', '◼️', '◾', '◼️', '✒️', '▪️', '💣', '🎳', '📷', '📸', '♣️', '🕶️', '✴️', '🔌', '💂‍♀️', '📽️', '🍳', '🦍', '💂', '🔪', '🕳️', '🕹️', '🕋', '🖊️', '🖋️', '💂‍♂️', '🎤', '🎓', '🎥', '🎼', '♠️', '🎩', '🦃', '📼', '📹', '🎮', '🐃', '🏴', '🐞', '🕺', '📱', '📲']);
+const darkEmoji = emojiFilenames(['🎱', '🐜', '⚫', '🖤', '⬛', '◼️', '◾', '◼️', '✒️', '▪️', '💣', '🎳', '📷', '📸', '♣️', '🕶️', '✴️', '🔌', '💂‍♀️', '📽️', '🍳', '🦍', '💂', '🔪', '🕳️', '🕹️', '🕋', '🖊️', '🖋️', '💂‍♂️', '🎤', '🎓', '🎥', '🎼', '♠️', '🎩', '🦃', '📼', '📹', '🎮', '🐃', '🏴', '🐞', '🕺', '📱', '📲', '🚲']);
 const lightEmoji = emojiFilenames(['👽', '⚾', '🐔', '☁️', '💨', '🕊️', '👀', '🍥', '👻', '🐐', '❕', '❔', '⛸️', '🌩️', '🔊', '🔇', '📃', '🌧️', '🐏', '🍚', '🍙', '🐓', '🐑', '💀', '☠️', '🌨️', '🔉', '🔈', '💬', '💭', '🏐', '🏳️', '⚪', '⬜', '◽', '◻️', '▫️']);
 
 const emojiFilename = (filename) => {
diff --git a/app/javascript/mastodon/features/follow_recommendations/components/account.js b/app/javascript/mastodon/features/follow_recommendations/components/account.js
new file mode 100644
index 000000000..bd855aab0
--- /dev/null
+++ b/app/javascript/mastodon/features/follow_recommendations/components/account.js
@@ -0,0 +1,85 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import ImmutablePropTypes from 'react-immutable-proptypes';
+import ImmutablePureComponent from 'react-immutable-pure-component';
+import { connect } from 'react-redux';
+import { makeGetAccount } from 'mastodon/selectors';
+import Avatar from 'mastodon/components/avatar';
+import DisplayName from 'mastodon/components/display_name';
+import Permalink from 'mastodon/components/permalink';
+import IconButton from 'mastodon/components/icon_button';
+import { injectIntl, defineMessages } from 'react-intl';
+import { followAccount, unfollowAccount } from 'mastodon/actions/accounts';
+
+const messages = defineMessages({
+  follow: { id: 'account.follow', defaultMessage: 'Follow' },
+  unfollow: { id: 'account.unfollow', defaultMessage: 'Unfollow' },
+});
+
+const makeMapStateToProps = () => {
+  const getAccount = makeGetAccount();
+
+  const mapStateToProps = (state, props) => ({
+    account: getAccount(state, props.id),
+  });
+
+  return mapStateToProps;
+};
+
+const getFirstSentence = str => {
+  const arr = str.split(/(([\.\?!]+\s)|[．。？！\n•])/);
+
+  return arr[0];
+};
+
+export default @connect(makeMapStateToProps)
+@injectIntl
+class Account extends ImmutablePureComponent {
+
+  static propTypes = {
+    account: ImmutablePropTypes.map.isRequired,
+    intl: PropTypes.object.isRequired,
+    dispatch: PropTypes.func.isRequired,
+  };
+
+  handleFollow = () => {
+    const { account, dispatch } = this.props;
+
+    if (account.getIn(['relationship', 'following']) || account.getIn(['relationship', 'requested'])) {
+      dispatch(unfollowAccount(account.get('id')));
+    } else {
+      dispatch(followAccount(account.get('id')));
+    }
+  }
+
+  render () {
+    const { account, intl } = this.props;
+
+    let button;
+
+    if (account.getIn(['relationship', 'following'])) {
+      button = <IconButton icon='check' title={intl.formatMessage(messages.unfollow)} active onClick={this.handleFollow} />;
+    } else {
+      button = <IconButton icon='plus' title={intl.formatMessage(messages.follow)} onClick={this.handleFollow} />;
+    }
+
+    return (
+      <div className='account follow-recommendations-account'>
+        <div className='account__wrapper'>
+          <Permalink className='account__display-name account__display-name--with-note' title={account.get('acct')} href={account.get('url')} to={`/accounts/${account.get('id')}`}>
+            <div className='account__avatar-wrapper'><Avatar account={account} size={36} /></div>
+
+            <DisplayName account={account} />
+
+            <div className='account__note'>{getFirstSentence(account.get('note_plain'))}</div>
+          </Permalink>
+
+          <div className='account__relationship'>
+            {button}
+          </div>
+        </div>
+      </div>
+    );
+  }
+
+}
diff --git a/app/javascript/mastodon/features/follow_recommendations/index.js b/app/javascript/mastodon/features/follow_recommendations/index.js
new file mode 100644
index 000000000..1231a27ea
--- /dev/null
+++ b/app/javascript/mastodon/features/follow_recommendations/index.js
@@ -0,0 +1,95 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import ImmutablePureComponent from 'react-immutable-pure-component';
+import ImmutablePropTypes from 'react-immutable-proptypes';
+import { connect } from 'react-redux';
+import { FormattedMessage } from 'react-intl';
+import { fetchSuggestions } from 'mastodon/actions/suggestions';
+import { changeSetting, saveSettings } from 'mastodon/actions/settings';
+import { requestBrowserPermission } from 'mastodon/actions/notifications';
+import Column from 'mastodon/features/ui/components/column';
+import Account from './components/account';
+import Logo from 'mastodon/components/logo';
+import imageGreeting from 'mastodon/../images/elephant_ui_greeting.svg';
+import Button from 'mastodon/components/button';
+
+const mapStateToProps = state => ({
+  suggestions: state.getIn(['suggestions', 'items']),
+  isLoading: state.getIn(['suggestions', 'isLoading']),
+});
+
+export default @connect(mapStateToProps)
+class FollowRecommendations extends ImmutablePureComponent {
+
+  static contextTypes = {
+    router: PropTypes.object.isRequired,
+  };
+
+  static propTypes = {
+    dispatch: PropTypes.func.isRequired,
+    suggestions: ImmutablePropTypes.list,
+    isLoading: PropTypes.bool,
+  };
+
+  componentDidMount () {
+    const { dispatch, suggestions } = this.props;
+
+    // Don't re-fetch if we're e.g. navigating backwards to this page,
+    // since we don't want followed accounts to disappear from the list
+
+    if (suggestions.size === 0) {
+      dispatch(fetchSuggestions(true));
+    }
+  }
+
+  handleDone = () => {
+    const { dispatch } = this.props;
+    const { router } = this.context;
+
+    dispatch(requestBrowserPermission((permission) => {
+      if (permission === 'granted') {
+        dispatch(changeSetting(['notifications', 'alerts', 'follow'], true));
+        dispatch(changeSetting(['notifications', 'alerts', 'favourite'], true));
+        dispatch(changeSetting(['notifications', 'alerts', 'reblog'], true));
+        dispatch(changeSetting(['notifications', 'alerts', 'mention'], true));
+        dispatch(changeSetting(['notifications', 'alerts', 'poll'], true));
+        dispatch(changeSetting(['notifications', 'alerts', 'status'], true));
+        dispatch(saveSettings());
+      }
+    }));
+
+    router.history.push('/timelines/home');
+  }
+
+  render () {
+    const { suggestions, isLoading } = this.props;
+
+    return (
+      <Column>
+        <div className='scrollable'>
+          <div className='column-title'>
+            <Logo />
+            <h3><FormattedMessage id='follow_recommendations.heading' defaultMessage="Follow people you'd like to see posts from! Here are some suggestions." /></h3>
+            <p><FormattedMessage id='follow_recommendations.lead' defaultMessage="Posts from people you follow will show up in chronological order on your home feed. Don't be afraid to make mistakes, you can unfollow people just as easily any time!" /></p>
+          </div>
+
+          {!isLoading && (
+            <React.Fragment>
+              <div>
+                {suggestions.map(suggestion => (
+                  <Account key={suggestion.get('account')} id={suggestion.get('account')} />
+                ))}
+              </div>
+
+              <div className='column-actions'>
+                <img src={imageGreeting} alt='' className='column-actions__background' />
+                <Button onClick={this.handleDone}><FormattedMessage id='follow_recommendations.done' defaultMessage='Done' /></Button>
+              </div>
+            </React.Fragment>
+          )}
+        </div>
+      </Column>
+    );
+  }
+
+}
diff --git a/app/javascript/mastodon/features/ui/index.js b/app/javascript/mastodon/features/ui/index.js
index 507ac1df1..078a69f0f 100644
--- a/app/javascript/mastodon/features/ui/index.js
+++ b/app/javascript/mastodon/features/ui/index.js
@@ -51,10 +51,12 @@ import {
   Lists,
   Search,
   Directory,
+  FollowRecommendations,
 } from './util/async-components';
 import { me } from '../../initial_state';
 import { previewState as previewMediaState } from './components/media_modal';
 import { previewState as previewVideoState } from './components/video_modal';
+import { closeOnboarding, INTRODUCTION_VERSION } from 'mastodon/actions/onboarding';
 
 // Dummy import, to make sure that <Status /> ends up in the application bundle.
 // Without this it ends up in ~8 very commonly used bundles.
@@ -71,6 +73,7 @@ const mapStateToProps = state => ({
   hasMediaAttachments: state.getIn(['compose', 'media_attachments']).size > 0,
   canUploadMore: !state.getIn(['compose', 'media_attachments']).some(x => ['audio', 'video'].includes(x.get('type'))) && state.getIn(['compose', 'media_attachments']).size < 4,
   dropdownMenuIsOpen: state.getIn(['dropdown_menu', 'openId']) !== null,
+  firstLaunch: state.getIn(['settings', 'introductionVersion'], 0) < INTRODUCTION_VERSION,
 });
 
 const keyMap = {
@@ -167,6 +170,7 @@ class SwitchingColumnsArea extends React.PureComponent {
           <WrappedRoute path='/bookmarks' component={BookmarkedStatuses} content={children} />
           <WrappedRoute path='/pinned' component={PinnedStatuses} content={children} componentParams={{ shouldUpdateScroll: this.shouldUpdateScroll }} />
 
+          <WrappedRoute path='/start' component={FollowRecommendations} content={children} />
           <WrappedRoute path='/search' component={Search} content={children} />
           <WrappedRoute path='/directory' component={Directory} content={children} componentParams={{ shouldUpdateScroll: this.shouldUpdateScroll }} />
 
@@ -215,6 +219,7 @@ class UI extends React.PureComponent {
     intl: PropTypes.object.isRequired,
     dropdownMenuIsOpen: PropTypes.bool,
     layout: PropTypes.string.isRequired,
+    firstLaunch: PropTypes.bool,
   };
 
   state = {
@@ -350,6 +355,12 @@ class UI extends React.PureComponent {
       navigator.serviceWorker.addEventListener('message', this.handleServiceWorkerPostMessage);
     }
 
+    // On first launch, redirect to the follow recommendations page
+    if (this.props.firstLaunch) {
+      this.context.router.history.replace('/start');
+      this.props.dispatch(closeOnboarding());
+    }
+
     this.props.dispatch(fetchMarkers());
     this.props.dispatch(expandHomeTimeline());
     this.props.dispatch(expandNotifications());
diff --git a/app/javascript/mastodon/features/ui/util/async-components.js b/app/javascript/mastodon/features/ui/util/async-components.js
index 986efda1e..aa90b226a 100644
--- a/app/javascript/mastodon/features/ui/util/async-components.js
+++ b/app/javascript/mastodon/features/ui/util/async-components.js
@@ -153,3 +153,7 @@ export function Audio () {
 export function Directory () {
   return import(/* webpackChunkName: "features/directory" */'../../directory');
 }
+
+export function FollowRecommendations () {
+  return import(/* webpackChunkName: "features/follow_recommendations" */'../../follow_recommendations');
+}
diff --git a/app/javascript/mastodon/reducers/suggestions.js b/app/javascript/mastodon/reducers/suggestions.js
index 834be728f..1a6e66ee7 100644
--- a/app/javascript/mastodon/reducers/suggestions.js
+++ b/app/javascript/mastodon/reducers/suggestions.js
@@ -19,18 +19,18 @@ export default function suggestionsReducer(state = initialState, action) {
     return state.set('isLoading', true);
   case SUGGESTIONS_FETCH_SUCCESS:
     return state.withMutations(map => {
-      map.set('items', fromJS(action.accounts.map(x => x.id)));
+      map.set('items', fromJS(action.suggestions.map(x => ({ ...x, account: x.account.id }))));
       map.set('isLoading', false);
     });
   case SUGGESTIONS_FETCH_FAIL:
     return state.set('isLoading', false);
   case SUGGESTIONS_DISMISS:
-    return state.update('items', list => list.filterNot(id => id === action.id));
+    return state.update('items', list => list.filterNot(x => x.account === action.id));
   case ACCOUNT_BLOCK_SUCCESS:
   case ACCOUNT_MUTE_SUCCESS:
-    return state.update('items', list => list.filterNot(id => id === action.relationship.id));
+    return state.update('items', list => list.filterNot(x => x.account === action.relationship.id));
   case DOMAIN_BLOCK_SUCCESS:
-    return state.update('items', list => list.filterNot(id => action.accounts.includes(id)));
+    return state.update('items', list => list.filterNot(x => action.accounts.includes(x.account)));
   default:
     return state;
   }
diff --git a/app/javascript/styles/mastodon/components.scss b/app/javascript/styles/mastodon/components.scss
index 2059aa8f3..a359af2ca 100644
--- a/app/javascript/styles/mastodon/components.scss
+++ b/app/javascript/styles/mastodon/components.scss
@@ -1307,6 +1307,29 @@
     overflow: hidden;
     text-decoration: none;
     font-size: 14px;
+
+    &--with-note {
+      strong {
+        display: inline;
+      }
+    }
+  }
+
+  &__note {
+    white-space: nowrap;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    color: $ui-secondary-color;
+  }
+}
+
+.follow-recommendations-account {
+  .icon-button {
+    color: $ui-primary-color;
+
+    &.active {
+      color: $valid-value-color;
+    }
   }
 }
 
@@ -2459,6 +2482,49 @@ a.account__display-name {
   border-color: darken($ui-base-color, 8%);
 }
 
+.column-title {
+  text-align: center;
+  padding: 40px;
+
+  .logo {
+    fill: $primary-text-color;
+    width: 50px;
+    margin: 0 auto;
+    margin-bottom: 40px;
+  }
+
+  h3 {
+    font-size: 24px;
+    line-height: 1.5;
+    font-weight: 700;
+    margin-bottom: 10px;
+  }
+
+  p {
+    font-size: 16px;
+    line-height: 24px;
+    font-weight: 400;
+    color: $darker-text-color;
+  }
+}
+
+.column-actions {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  padding: 40px;
+  padding-top: 40px;
+  padding-bottom: 200px;
+
+  &__background {
+    position: absolute;
+    left: 0;
+    bottom: 0;
+    height: 220px;
+    width: auto;
+  }
+}
+
 .compose-panel {
   width: 285px;
   margin-top: 10px;
diff --git a/app/lib/account_reach_finder.rb b/app/lib/account_reach_finder.rb
new file mode 100644
index 000000000..706ce8c1f
--- /dev/null
+++ b/app/lib/account_reach_finder.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+class AccountReachFinder
+  def initialize(account)
+    @account = account
+  end
+
+  def inboxes
+    (followers_inboxes + reporters_inboxes + relay_inboxes).uniq
+  end
+
+  private
+
+  def followers_inboxes
+    @account.followers.inboxes
+  end
+
+  def reporters_inboxes
+    Account.where(id: @account.targeted_reports.select(:account_id)).inboxes
+  end
+
+  def relay_inboxes
+    Relay.enabled.pluck(:inbox_url)
+  end
+end
diff --git a/app/lib/activitypub/activity/create.rb b/app/lib/activitypub/activity/create.rb
index f10fc5f43..3a73f29ae 100644
--- a/app/lib/activitypub/activity/create.rb
+++ b/app/lib/activitypub/activity/create.rb
@@ -88,7 +88,6 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
 
     resolve_thread(@status)
     fetch_replies(@status)
-    check_for_spam
     distribute(@status)
     forward_for_reply
   end
@@ -498,10 +497,6 @@ class ActivityPub::Activity::Create < ActivityPub::Activity
     Tombstone.exists?(uri: object_uri)
   end
 
-  def check_for_spam
-    SpamCheck.perform(@status)
-  end
-
   def forward_for_reply
     return unless @status.distributable? && @json['signature'].present? && reply_to_local?
 
diff --git a/app/lib/activitypub/activity/flag.rb b/app/lib/activitypub/activity/flag.rb
index 8dfc76f0a..b0443849a 100644
--- a/app/lib/activitypub/activity/flag.rb
+++ b/app/lib/activitypub/activity/flag.rb
@@ -10,6 +10,8 @@ class ActivityPub::Activity::Flag < ActivityPub::Activity
     target_accounts.each do |target_account|
       target_statuses = target_statuses_by_account[target_account.id]
 
+      next if target_account.suspended?
+
       ReportService.new.call(
         @account,
         target_account,
diff --git a/app/lib/admin/system_check/sidekiq_process_check.rb b/app/lib/admin/system_check/sidekiq_process_check.rb
index c44d86c44..22446edaf 100644
--- a/app/lib/admin/system_check/sidekiq_process_check.rb
+++ b/app/lib/admin/system_check/sidekiq_process_check.rb
@@ -7,7 +7,6 @@ class Admin::SystemCheck::SidekiqProcessCheck < Admin::SystemCheck::BaseCheck
     mailers
     pull
     scheduler
-    ingress
   ).freeze
 
   def pass?
diff --git a/app/lib/application_extension.rb b/app/lib/application_extension.rb
index 1d80b8c6d..e61cd0721 100644
--- a/app/lib/application_extension.rb
+++ b/app/lib/application_extension.rb
@@ -4,6 +4,8 @@ module ApplicationExtension
   extend ActiveSupport::Concern
 
   included do
-    validates :website, url: true, if: :website?
+    validates :name, length: { maximum: 60 }
+    validates :website, url: true, length: { maximum: 2_000 }, if: :website?
+    validates :redirect_uri, length: { maximum: 2_000 }
   end
 end
diff --git a/app/lib/formatter.rb b/app/lib/formatter.rb
index 02ebe6f89..b26138642 100644
--- a/app/lib/formatter.rb
+++ b/app/lib/formatter.rb
@@ -118,7 +118,7 @@ class Formatter
   end
 
   def format_field(account, str, **options)
-    html = account.local? ? encode_and_link_urls(str, me: true) : reformat(str)
+    html = account.local? ? encode_and_link_urls(str, me: true, with_domain: true) : reformat(str)
     html = encode_custom_emojis(html, account.emojis, options[:autoplay]) if options[:custom_emojify]
     html.html_safe # rubocop:disable Rails/OutputSafety
   end
@@ -187,7 +187,7 @@ class Formatter
       elsif entity[:hashtag]
         link_to_hashtag(entity)
       elsif entity[:screen_name]
-        link_to_mention(entity, accounts)
+        link_to_mention(entity, accounts, options)
       end
     end
   end
@@ -352,22 +352,37 @@ class Formatter
     encode(entity[:url])
   end
 
-  def link_to_mention(entity, linkable_accounts)
+  def link_to_mention(entity, linkable_accounts, options = {})
     acct = entity[:screen_name]
 
-    return link_to_account(acct) unless linkable_accounts
+    return link_to_account(acct, options) unless linkable_accounts
 
-    account = linkable_accounts.find { |item| TagManager.instance.same_acct?(item.acct, acct) }
-    account ? mention_html(account) : "@#{encode(acct)}"
+    same_username_hits = 0
+    account = nil
+    username, domain = acct.split('@')
+    domain = nil if TagManager.instance.local_domain?(domain)
+
+    linkable_accounts.each do |item|
+      same_username = item.username.casecmp(username).zero?
+      same_domain   = item.domain.nil? ? domain.nil? : item.domain.casecmp(domain)&.zero?
+
+      if same_username && !same_domain
+        same_username_hits += 1
+      elsif same_username && same_domain
+        account = item
+      end
+    end
+
+    account ? mention_html(account, with_domain: same_username_hits.positive? || options[:with_domain]) : "@#{encode(acct)}"
   end
 
-  def link_to_account(acct)
+  def link_to_account(acct, options = {})
     username, domain = acct.split('@')
 
     domain  = nil if TagManager.instance.local_domain?(domain)
     account = EntityCache.instance.mention(username, domain)
 
-    account ? mention_html(account) : "@#{encode(acct)}"
+    account ? mention_html(account, with_domain: options[:with_domain]) : "@#{encode(acct)}"
   end
 
   def link_to_hashtag(entity)
@@ -388,7 +403,7 @@ class Formatter
     "<a href=\"#{encode(tag_url(tag))}\" class=\"mention hashtag\" rel=\"tag\">#<span>#{encode(tag)}</span></a>"
   end
 
-  def mention_html(account)
-    "<span class=\"h-card\"><a href=\"#{encode(ActivityPub::TagManager.instance.url_for(account))}\" class=\"u-url mention\">@<span>#{encode(account.username)}</span></a></span>"
+  def mention_html(account, with_domain: false)
+    "<span class=\"h-card\"><a href=\"#{encode(ActivityPub::TagManager.instance.url_for(account))}\" class=\"u-url mention\">@<span>#{encode(with_domain ? account.pretty_acct : account.username)}</span></a></span>"
   end
 end
diff --git a/app/lib/potential_friendship_tracker.rb b/app/lib/potential_friendship_tracker.rb
index 188aa4a27..e72d454b6 100644
--- a/app/lib/potential_friendship_tracker.rb
+++ b/app/lib/potential_friendship_tracker.rb
@@ -28,10 +28,14 @@ class PotentialFriendshipTracker
       redis.zrem("interactions:#{account_id}", target_account_id)
     end
 
-    def get(account_id, limit: 20, offset: 0)
-      account_ids = redis.zrevrange("interactions:#{account_id}", offset, limit)
-      return [] if account_ids.empty?
-      Account.searchable.where(id: account_ids)
+    def get(account, limit)
+      account_ids = redis.zrevrange("interactions:#{account.id}", 0, limit)
+
+      return [] if account_ids.empty? || limit < 1
+
+      accounts = Account.searchable.where(id: account_ids).index_by(&:id)
+
+      account_ids.map { |id| accounts[id.to_i] }.compact
     end
   end
 end
diff --git a/app/lib/spam_check.rb b/app/lib/spam_check.rb
deleted file mode 100644
index dcb2db9ca..000000000
--- a/app/lib/spam_check.rb
+++ /dev/null
@@ -1,198 +0,0 @@
-# frozen_string_literal: true
-
-class SpamCheck
-  include Redisable
-  include ActionView::Helpers::TextHelper
-
-  # Threshold over which two Nilsimsa values are considered
-  # to refer to the same text
-  NILSIMSA_COMPARE_THRESHOLD = 95
-
-  # Nilsimsa doesn't work well on small inputs, so below
-  # this size, we check only for exact matches with MD5
-  NILSIMSA_MIN_SIZE = 10
-
-  # How long to keep the trail of digests between updates,
-  # there is no reason to store it forever
-  EXPIRE_SET_AFTER = 1.week.seconds
-
-  # How many digests to keep in an account's trail. If it's
-  # too small, spam could rotate around different message templates
-  MAX_TRAIL_SIZE = 10
-
-  # How many detected duplicates to allow through before
-  # considering the message as spam
-  THRESHOLD = 5
-
-  def initialize(status)
-    @account = status.account
-    @status  = status
-  end
-
-  def skip?
-    disabled? || already_flagged? || trusted? || no_unsolicited_mentions? || solicited_reply?
-  end
-
-  def spam?
-    if insufficient_data?
-      false
-    elsif nilsimsa?
-      digests_over_threshold?('nilsimsa') { |_, other_digest| nilsimsa_compare_value(digest, other_digest) >= NILSIMSA_COMPARE_THRESHOLD }
-    else
-      digests_over_threshold?('md5') { |_, other_digest| other_digest == digest }
-    end
-  end
-
-  def flag!
-    auto_report_status!
-  end
-
-  def remember!
-    # The scores in sorted sets don't actually have enough bits to hold an exact
-    # value of our snowflake IDs, so we use it only for its ordering property. To
-    # get the correct status ID back, we have to save it in the string value
-
-    redis.zadd(redis_key, @status.id, digest_with_algorithm)
-    redis.zremrangebyrank(redis_key, 0, -(MAX_TRAIL_SIZE + 1))
-    redis.expire(redis_key, EXPIRE_SET_AFTER)
-  end
-
-  def reset!
-    redis.del(redis_key)
-  end
-
-  def hashable_text
-    return @hashable_text if defined?(@hashable_text)
-
-    @hashable_text = @status.text
-    @hashable_text = remove_mentions(@hashable_text)
-    @hashable_text = strip_tags(@hashable_text) unless @status.local?
-    @hashable_text = normalize_unicode(@status.spoiler_text + ' ' + @hashable_text)
-    @hashable_text = remove_whitespace(@hashable_text)
-  end
-
-  def insufficient_data?
-    hashable_text.blank?
-  end
-
-  def digest
-    @digest ||= begin
-      if nilsimsa?
-        Nilsimsa.new(hashable_text).hexdigest
-      else
-        Digest::MD5.hexdigest(hashable_text)
-      end
-    end
-  end
-
-  def digest_with_algorithm
-    if nilsimsa?
-      ['nilsimsa', digest, @status.id].join(':')
-    else
-      ['md5', digest, @status.id].join(':')
-    end
-  end
-
-  class << self
-    def perform(status)
-      spam_check = new(status)
-
-      return if spam_check.skip?
-
-      if spam_check.spam?
-        spam_check.flag!
-      else
-        spam_check.remember!
-      end
-    end
-  end
-
-  private
-
-  def disabled?
-    !Setting.spam_check_enabled
-  end
-
-  def remove_mentions(text)
-    return text.gsub(Account::MENTION_RE, '') if @status.local?
-
-    Nokogiri::HTML.fragment(text).tap do |html|
-      mentions = @status.mentions.map { |mention| ActivityPub::TagManager.instance.url_for(mention.account) }
-
-      html.traverse do |element|
-        element.unlink if element.name == 'a' && mentions.include?(element['href'])
-      end
-    end.to_s
-  end
-
-  def normalize_unicode(text)
-    text.unicode_normalize(:nfkc).downcase
-  end
-
-  def remove_whitespace(text)
-    text.gsub(/\s+/, ' ').strip
-  end
-
-  def auto_report_status!
-    status_ids = Status.where(visibility: %i(public unlisted)).where(id: matching_status_ids).pluck(:id) + [@status.id] if @status.distributable?
-    ReportService.new.call(Account.representative, @account, status_ids: status_ids, comment: I18n.t('spam_check.spam_detected'))
-  end
-
-  def already_flagged?
-    @account.silenced? || @account.targeted_reports.unresolved.where(account_id: -99).exists?
-  end
-
-  def trusted?
-    @account.trust_level > Account::TRUST_LEVELS[:untrusted] || (@account.local? && @account.user_staff?)
-  end
-
-  def no_unsolicited_mentions?
-    @status.mentions.all? { |mention| mention.silent? || (!@account.local? && !mention.account.local?) || mention.account.following?(@account) }
-  end
-
-  def solicited_reply?
-    !@status.thread.nil? && @status.thread.mentions.where(account: @account).exists?
-  end
-
-  def nilsimsa_compare_value(first, second)
-    first  = [first].pack('H*')
-    second = [second].pack('H*')
-    bits   = 0
-
-    0.upto(31) do |i|
-      bits += Nilsimsa::POPC[255 & (first[i].ord ^ second[i].ord)].ord
-    end
-
-    128 - bits # -128 <= Nilsimsa Compare Value <= 128
-  end
-
-  def nilsimsa?
-    hashable_text.size > NILSIMSA_MIN_SIZE
-  end
-
-  def other_digests
-    redis.zrange(redis_key, 0, -1)
-  end
-
-  def digests_over_threshold?(filter_algorithm)
-    other_digests.select do |record|
-      algorithm, other_digest, status_id = record.split(':')
-
-      next unless algorithm == filter_algorithm
-
-      yield algorithm, other_digest, status_id
-    end.size >= THRESHOLD
-  end
-
-  def matching_status_ids
-    if nilsimsa?
-      other_digests.filter_map { |record| record.split(':')[2] if record.start_with?('nilsimsa') && nilsimsa_compare_value(digest, record.split(':')[1]) >= NILSIMSA_COMPARE_THRESHOLD }
-    else
-      other_digests.filter_map { |record| record.split(':')[2] if record.start_with?('md5') && record.split(':')[1] == digest }
-    end
-  end
-
-  def redis_key
-    @redis_key ||= "spam_check:#{@account.id}"
-  end
-end
diff --git a/app/lib/status_reach_finder.rb b/app/lib/status_reach_finder.rb
index 35b191dad..3aab3bde0 100644
--- a/app/lib/status_reach_finder.rb
+++ b/app/lib/status_reach_finder.rb
@@ -6,11 +6,22 @@ class StatusReachFinder
   end
 
   def inboxes
-    Account.where(id: reached_account_ids).inboxes
+    (reached_account_inboxes + followers_inboxes + relay_inboxes).uniq
   end
 
   private
 
+  def reached_account_inboxes
+    # When the status is a reblog, there are no interactions with it
+    # directly, we assume all interactions are with the original one
+
+    if @status.reblog?
+      []
+    else
+      Account.where(id: reached_account_ids).inboxes
+    end
+  end
+
   def reached_account_ids
     [
       replied_to_account_id,
@@ -49,4 +60,16 @@ class StatusReachFinder
   def replies_account_ids
     @status.replies.pluck(:account_id)
   end
+
+  def followers_inboxes
+    @status.account.followers.inboxes
+  end
+
+  def relay_inboxes
+    if @status.public_visibility?
+      Relay.enabled.pluck(:inbox_url)
+    else
+      []
+    end
+  end
 end
diff --git a/app/lib/tag_manager.rb b/app/lib/tag_manager.rb
index 29dde128c..a1d12a654 100644
--- a/app/lib/tag_manager.rb
+++ b/app/lib/tag_manager.rb
@@ -22,14 +22,6 @@ class TagManager
     uri.normalized_host
   end
 
-  def same_acct?(canonical, needle)
-    return true if canonical.casecmp(needle).zero?
-
-    username, domain = needle.split('@')
-
-    local_domain?(domain) && canonical.casecmp(username).zero?
-  end
-
   def local_url?(url)
     uri    = Addressable::URI.parse(url).normalize
     return false unless uri.host
diff --git a/app/models/account.rb b/app/models/account.rb
index 2e7d9f543..8f042c931 100644
--- a/app/models/account.rb
+++ b/app/models/account.rb
@@ -114,6 +114,7 @@ class Account < ApplicationRecord
   scope :matches_domain, ->(value) { where(arel_table[:domain].matches("%#{value}%")) }
   scope :searchable, -> { without_suspended.where(moved_to_account_id: nil) }
   scope :discoverable, -> { searchable.without_silenced.where(discoverable: true).left_outer_joins(:account_stat) }
+  scope :followable_by, ->(account) { joins(arel_table.join(Follow.arel_table, Arel::Nodes::OuterJoin).on(arel_table[:id].eq(Follow.arel_table[:target_account_id]).and(Follow.arel_table[:account_id].eq(account.id))).join_sources).where(Follow.arel_table[:id].eq(nil)).joins(arel_table.join(FollowRequest.arel_table, Arel::Nodes::OuterJoin).on(arel_table[:id].eq(FollowRequest.arel_table[:target_account_id]).and(FollowRequest.arel_table[:account_id].eq(account.id))).join_sources).where(FollowRequest.arel_table[:id].eq(nil)) }
   scope :tagged_with, ->(tag) { joins(:accounts_tags).where(accounts_tags: { tag_id: tag }) }
   scope :by_recent_status, -> { order(Arel.sql('(case when account_stats.last_status_at is null then 1 else 0 end) asc, account_stats.last_status_at desc, accounts.id desc')) }
   scope :by_recent_sign_in, -> { order(Arel.sql('(case when users.current_sign_in_at is null then 1 else 0 end) asc, users.current_sign_in_at desc, accounts.id desc')) }
@@ -238,6 +239,7 @@ class Account < ApplicationRecord
     transaction do
       create_deletion_request!
       update!(suspended_at: date, suspension_origin: origin)
+      create_canonical_email_block!
     end
   end
 
@@ -245,6 +247,7 @@ class Account < ApplicationRecord
     transaction do
       deletion_request&.destroy!
       update!(suspended_at: nil, suspension_origin: nil)
+      destroy_canonical_email_block!
     end
   end
 
@@ -365,7 +368,7 @@ class Account < ApplicationRecord
   end
 
   def excluded_from_timeline_account_ids
-    Rails.cache.fetch("exclude_account_ids_for:#{id}") { blocking.pluck(:target_account_id) + blocked_by.pluck(:account_id) + muting.pluck(:target_account_id) }
+    Rails.cache.fetch("exclude_account_ids_for:#{id}") { block_relationships.pluck(:target_account_id) + blocked_by_relationships.pluck(:account_id) + mute_relationships.pluck(:target_account_id) }
   end
 
   def excluded_from_timeline_domains
@@ -570,4 +573,16 @@ class Account < ApplicationRecord
   def clean_feed_manager
     FeedManager.instance.clean_feeds!(:home, [id])
   end
+
+  def create_canonical_email_block!
+    return unless local? && user_email.present?
+
+    CanonicalEmailBlock.create(reference_account: self, email: user_email)
+  end
+
+  def destroy_canonical_email_block!
+    return unless local?
+
+    CanonicalEmailBlock.where(reference_account: self).delete_all
+  end
 end
diff --git a/app/models/account_suggestions.rb b/app/models/account_suggestions.rb
new file mode 100644
index 000000000..7fe9d618e
--- /dev/null
+++ b/app/models/account_suggestions.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class AccountSuggestions
+  class Suggestion < ActiveModelSerializers::Model
+    attributes :account, :source
+  end
+
+  def self.get(account, limit)
+    suggestions = PotentialFriendshipTracker.get(account, limit).map { |target_account| Suggestion.new(account: target_account, source: :past_interaction) }
+    suggestions.concat(FollowRecommendation.get(account, limit - suggestions.size, suggestions.map { |suggestion| suggestion.account.id }).map { |target_account| Suggestion.new(account: target_account, source: :global) }) if suggestions.size < limit
+    suggestions
+  end
+
+  def self.remove(account, target_account_id)
+    PotentialFriendshipTracker.remove(account.id, target_account_id)
+  end
+end
diff --git a/app/models/account_summary.rb b/app/models/account_summary.rb
new file mode 100644
index 000000000..6a7e17c6c
--- /dev/null
+++ b/app/models/account_summary.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: account_summaries
+#
+#  account_id :bigint(8)        primary key
+#  language   :string
+#  sensitive  :boolean
+#
+
+class AccountSummary < ApplicationRecord
+  self.primary_key = :account_id
+
+  scope :safe, -> { where(sensitive: false) }
+  scope :localized, ->(locale) { where(language: locale) }
+  scope :filtered, -> { joins(arel_table.join(FollowRecommendationSuppression.arel_table, Arel::Nodes::OuterJoin).on(arel_table[:account_id].eq(FollowRecommendationSuppression.arel_table[:account_id])).join_sources).where(FollowRecommendationSuppression.arel_table[:id].eq(nil)) }
+
+  def self.refresh
+    Scenic.database.refresh_materialized_view(table_name, concurrently: true, cascade: false)
+  end
+
+  def readonly?
+    true
+  end
+end
diff --git a/app/models/canonical_email_block.rb b/app/models/canonical_email_block.rb
new file mode 100644
index 000000000..a8546d65a
--- /dev/null
+++ b/app/models/canonical_email_block.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: canonical_email_blocks
+#
+#  id                   :bigint(8)        not null, primary key
+#  canonical_email_hash :string           default(""), not null
+#  reference_account_id :bigint(8)        not null
+#  created_at           :datetime         not null
+#  updated_at           :datetime         not null
+#
+
+class CanonicalEmailBlock < ApplicationRecord
+  include EmailHelper
+
+  belongs_to :reference_account, class_name: 'Account'
+
+  validates :canonical_email_hash, presence: true
+
+  def email=(email)
+    self.canonical_email_hash = email_to_canonical_email_hash(email)
+  end
+
+  def self.block?(email)
+    where(canonical_email_hash: email_to_canonical_email_hash(email)).exists?
+  end
+end
diff --git a/app/models/concerns/account_associations.rb b/app/models/concerns/account_associations.rb
index 98849f8fc..aaf371ebd 100644
--- a/app/models/concerns/account_associations.rb
+++ b/app/models/concerns/account_associations.rb
@@ -63,5 +63,8 @@ module AccountAssociations
 
     # Account deletion requests
     has_one :deletion_request, class_name: 'AccountDeletionRequest', inverse_of: :account, dependent: :destroy
+
+    # Follow recommendations
+    has_one :follow_recommendation_suppression, inverse_of: :account, dependent: :destroy
   end
 end
diff --git a/app/models/follow_recommendation.rb b/app/models/follow_recommendation.rb
new file mode 100644
index 000000000..c4355224d
--- /dev/null
+++ b/app/models/follow_recommendation.rb
@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: follow_recommendations
+#
+#  account_id :bigint(8)        primary key
+#  rank       :decimal(, )
+#  reason     :text             is an Array
+#
+
+class FollowRecommendation < ApplicationRecord
+  self.primary_key = :account_id
+
+  belongs_to :account_summary, foreign_key: :account_id
+  belongs_to :account, foreign_key: :account_id
+
+  scope :safe, -> { joins(:account_summary).merge(AccountSummary.safe) }
+  scope :localized, ->(locale) { joins(:account_summary).merge(AccountSummary.localized(locale)) }
+  scope :filtered, -> { joins(:account_summary).merge(AccountSummary.filtered) }
+
+  def readonly?
+    true
+  end
+
+  def self.get(account, limit, exclude_account_ids = [])
+    account_ids = Redis.current.zrevrange("follow_recommendations:#{account.user_locale}", 0, -1).map(&:to_i) - exclude_account_ids - [account.id]
+
+    return [] if account_ids.empty? || limit < 1
+
+    accounts = Account.followable_by(account)
+                      .not_excluded_by_account(account)
+                      .not_domain_blocked_by_account(account)
+                      .where(id: account_ids)
+                      .limit(limit)
+                      .index_by(&:id)
+
+    account_ids.map { |id| accounts[id] }.compact
+  end
+end
diff --git a/app/models/follow_recommendation_filter.rb b/app/models/follow_recommendation_filter.rb
new file mode 100644
index 000000000..acf03cd84
--- /dev/null
+++ b/app/models/follow_recommendation_filter.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+class FollowRecommendationFilter
+  KEYS = %i(
+    language
+    status
+  ).freeze
+
+  attr_reader :params, :language
+
+  def initialize(params)
+    @language = params.delete('language') || I18n.locale
+    @params   = params
+  end
+
+  def results
+    if params['status'] == 'suppressed'
+      Account.joins(:follow_recommendation_suppression).order(FollowRecommendationSuppression.arel_table[:id].desc).to_a
+    else
+      account_ids = Redis.current.zrevrange("follow_recommendations:#{@language}", 0, -1).map(&:to_i)
+      accounts    = Account.where(id: account_ids).index_by(&:id)
+
+      account_ids.map { |id| accounts[id] }.compact
+    end
+  end
+end
diff --git a/app/models/follow_recommendation_suppression.rb b/app/models/follow_recommendation_suppression.rb
new file mode 100644
index 000000000..170506b85
--- /dev/null
+++ b/app/models/follow_recommendation_suppression.rb
@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+# == Schema Information
+#
+# Table name: follow_recommendation_suppressions
+#
+#  id         :bigint(8)        not null, primary key
+#  account_id :bigint(8)        not null
+#  created_at :datetime         not null
+#  updated_at :datetime         not null
+#
+
+class FollowRecommendationSuppression < ApplicationRecord
+  include Redisable
+
+  belongs_to :account
+
+  after_commit :remove_follow_recommendations, on: :create
+
+  private
+
+  def remove_follow_recommendations
+    redis.pipelined do
+      I18n.available_locales.each do |locale|
+        redis.zrem("follow_recommendations:#{locale}", account_id)
+      end
+    end
+  end
+end
diff --git a/app/models/form/account_batch.rb b/app/models/form/account_batch.rb
index 26d6d3abf..698933c9f 100644
--- a/app/models/form/account_batch.rb
+++ b/app/models/form/account_batch.rb
@@ -21,6 +21,10 @@ class Form::AccountBatch
       approve!
     when 'reject'
       reject!
+    when 'suppress_follow_recommendation'
+      suppress_follow_recommendation!
+    when 'unsuppress_follow_recommendation'
+      unsuppress_follow_recommendation!
     end
   end
 
@@ -79,4 +83,18 @@ class Form::AccountBatch
     records.each { |account| authorize(account.user, :reject?) }
            .each { |account| DeleteAccountService.new.call(account, reserve_email: false, reserve_username: false) }
   end
+
+  def suppress_follow_recommendation!
+    authorize(:follow_recommendation, :suppress?)
+
+    accounts.each do |account|
+      FollowRecommendationSuppression.create(account: account)
+    end
+  end
+
+  def unsuppress_follow_recommendation!
+    authorize(:follow_recommendation, :unsuppress?)
+
+    FollowRecommendationSuppression.where(account_id: account_ids).destroy_all
+  end
 end
diff --git a/app/models/form/admin_settings.rb b/app/models/form/admin_settings.rb
index 999d835e6..558a906d2 100644
--- a/app/models/form/admin_settings.rb
+++ b/app/models/form/admin_settings.rb
@@ -35,7 +35,6 @@ class Form::AdminSettings
     mascot
     show_reblogs_in_public_timelines
     show_replies_in_public_timelines
-    spam_check_enabled
     trends
     trendable_by_default
     show_domain_blocks
@@ -59,7 +58,6 @@ class Form::AdminSettings
     enable_keybase
     show_reblogs_in_public_timelines
     show_replies_in_public_timelines
-    spam_check_enabled
     trends
     trendable_by_default
     noindex
diff --git a/app/models/web/push_subscription.rb b/app/models/web/push_subscription.rb
index c407a7789..6e46573ae 100644
--- a/app/models/web/push_subscription.rb
+++ b/app/models/web/push_subscription.rb
@@ -24,81 +24,101 @@ class Web::PushSubscription < ApplicationRecord
   validates :key_p256dh, presence: true
   validates :key_auth, presence: true
 
-  def push(notification)
-    I18n.with_locale(associated_user&.locale || I18n.default_locale) do
-      push_payload(payload_for_notification(notification), 48.hours.seconds)
-    end
+  delegate :locale, to: :associated_user
+
+  def encrypt(payload)
+    Webpush::Encryption.encrypt(payload, key_p256dh, key_auth)
+  end
+
+  def audience
+    @audience ||= Addressable::URI.parse(endpoint).normalized_site
+  end
+
+  def crypto_key_header
+    p256ecdsa = vapid_key.public_key_for_push_header
+
+    "p256ecdsa=#{p256ecdsa}"
+  end
+
+  def authorization_header
+    jwt = JWT.encode({ aud: audience, exp: 24.hours.from_now.to_i, sub: "mailto:#{contact_email}" }, vapid_key.curve, 'ES256', typ: 'JWT')
+
+    "WebPush #{jwt}"
   end
 
   def pushable?(notification)
-    data&.key?('alerts') && ActiveModel::Type::Boolean.new.cast(data['alerts'][notification.type.to_s])
+    policy_allows_notification?(notification) && alert_enabled_for_notification_type?(notification)
   end
 
   def associated_user
     return @associated_user if defined?(@associated_user)
 
-    @associated_user = if user_id.nil?
-                         session_activation.user
-                       else
-                         user
-                       end
+    @associated_user = begin
+      if user_id.nil?
+        session_activation.user
+      else
+        user
+      end
+    end
   end
 
   def associated_access_token
     return @associated_access_token if defined?(@associated_access_token)
 
-    @associated_access_token = if access_token_id.nil?
-                                 find_or_create_access_token.token
-                               else
-                                 access_token.token
-                               end
+    @associated_access_token = begin
+      if access_token_id.nil?
+        find_or_create_access_token.token
+      else
+        access_token.token
+      end
+    end
   end
 
   class << self
     def unsubscribe_for(application_id, resource_owner)
-      access_token_ids = Doorkeeper::AccessToken.where(application_id: application_id, resource_owner_id: resource_owner.id, revoked_at: nil)
-                                                .pluck(:id)
-
+      access_token_ids = Doorkeeper::AccessToken.where(application_id: application_id, resource_owner_id: resource_owner.id, revoked_at: nil).pluck(:id)
       where(access_token_id: access_token_ids).delete_all
     end
   end
 
   private
 
-  def push_payload(message, ttl = 5.minutes.seconds)
-    Webpush.payload_send(
-      message: Oj.dump(message),
-      endpoint: endpoint,
-      p256dh: key_p256dh,
-      auth: key_auth,
-      ttl: ttl,
-      ssl_timeout: 10,
-      open_timeout: 10,
-      read_timeout: 10,
-      vapid: {
-        subject: "mailto:#{::Setting.site_contact_email}",
-        private_key: Rails.configuration.x.vapid_private_key,
-        public_key: Rails.configuration.x.vapid_public_key,
-      }
-    )
-  end
-
-  def payload_for_notification(notification)
-    ActiveModelSerializers::SerializableResource.new(
-      notification,
-      serializer: Web::NotificationSerializer,
-      scope: self,
-      scope_name: :current_push_subscription
-    ).as_json
-  end
-
   def find_or_create_access_token
     Doorkeeper::AccessToken.find_or_create_for(
       application: Doorkeeper::Application.find_by(superapp: true),
-      resource_owner: session_activation.user_id,
+      resource_owner: user_id || session_activation.user_id,
       scopes: Doorkeeper::OAuth::Scopes.from_string('read write follow push'),
       expires_in: Doorkeeper.configuration.access_token_expires_in,
       use_refresh_token: Doorkeeper.configuration.refresh_token_enabled?
     )
   end
+
+  def vapid_key
+    @vapid_key ||= Webpush::VapidKey.from_keys(Rails.configuration.x.vapid_public_key, Rails.configuration.x.vapid_private_key)
+  end
+
+  def contact_email
+    @contact_email ||= ::Setting.site_contact_email
+  end
+
+  def alert_enabled_for_notification_type?(notification)
+    truthy?(data&.dig('alerts', notification.type.to_s))
+  end
+
+  def policy_allows_notification?(notification)
+    case data&.dig('policy')
+    when nil, 'all'
+      true
+    when 'none'
+      false
+    when 'followed'
+      notification.account.following?(notification.from_account)
+    when 'follower'
+      notification.from_account.following?(notification.account)
+    end
+  end
+
+  def truthy?(val)
+    ActiveModel::Type::Boolean.new.cast(val)
+  end
 end
diff --git a/app/policies/follow_recommendation_policy.rb b/app/policies/follow_recommendation_policy.rb
new file mode 100644
index 000000000..68cd0e547
--- /dev/null
+++ b/app/policies/follow_recommendation_policy.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class FollowRecommendationPolicy < ApplicationPolicy
+  def show?
+    staff?
+  end
+
+  def suppress?
+    staff?
+  end
+
+  def unsuppress?
+    staff?
+  end
+end
diff --git a/app/serializers/rest/suggestion_serializer.rb b/app/serializers/rest/suggestion_serializer.rb
new file mode 100644
index 000000000..3d697fd9f
--- /dev/null
+++ b/app/serializers/rest/suggestion_serializer.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class REST::SuggestionSerializer < ActiveModel::Serializer
+  attributes :source
+
+  has_one :account, serializer: REST::AccountSerializer
+end
diff --git a/app/services/process_mentions_service.rb b/app/services/process_mentions_service.rb
index 570cd8272..ec4cb11f9 100644
--- a/app/services/process_mentions_service.rb
+++ b/app/services/process_mentions_service.rb
@@ -43,7 +43,6 @@ class ProcessMentionsService < BaseService
     end
 
     status.save!
-    check_for_spam(status)
 
     mentions.each { |mention| create_notification(mention) }
   end
@@ -72,8 +71,4 @@ class ProcessMentionsService < BaseService
   def resolve_account_service
     ResolveAccountService.new
   end
-
-  def check_for_spam(status)
-    SpamCheck.perform(status)
-  end
 end
diff --git a/app/services/remove_status_service.rb b/app/services/remove_status_service.rb
index 764ed288d..17868d4fd 100644
--- a/app/services/remove_status_service.rb
+++ b/app/services/remove_status_service.rb
@@ -27,10 +27,7 @@ class RemoveStatusService < BaseService
         # original object being removed implicitly removes reblogs
         # of it. The Delete activity of the original is forwarded
         # separately.
-        if @account.local? && !@options[:original_removed]
-          remove_from_remote_followers
-          remove_from_remote_reach
-        end
+        remove_from_remote_reach if @account.local? && !@options[:original_removed]
 
         # Since reblogs don't mention anyone, don't get reblogged,
         # favourited and don't contain their own media attachments
@@ -42,7 +39,6 @@ class RemoveStatusService < BaseService
           remove_from_public
           remove_from_media if @status.media_attachments.any?
           remove_from_direct if status.direct_visibility?
-          remove_from_spam_check
           remove_media
         end
 
@@ -85,13 +81,10 @@ class RemoveStatusService < BaseService
   end
 
   def remove_from_remote_reach
-    return if @status.reblog?
-
-    # People who got mentioned in the status, or who
-    # reblogged it from someone else might not follow
-    # the author and wouldn't normally receive the
-    # delete notification - so here, we explicitly
-    # send it to them
+    # Followers, relays, people who got mentioned in the status,
+    # or who reblogged it from someone else might not follow
+    # the author and wouldn't normally receive the delete
+    # notification - so here, we explicitly send it to them
 
     status_reach_finder = StatusReachFinder.new(@status)
 
@@ -100,24 +93,6 @@ class RemoveStatusService < BaseService
     end
   end
 
-  def remove_from_remote_followers
-    ActivityPub::DeliveryWorker.push_bulk(@account.followers.inboxes) do |inbox_url|
-      [signed_activity_json, @account.id, inbox_url]
-    end
-
-    relay! if relayable?
-  end
-
-  def relayable?
-    @status.public_visibility?
-  end
-
-  def relay!
-    ActivityPub::DeliveryWorker.push_bulk(Relay.enabled.pluck(:inbox_url)) do |inbox_url|
-      [signed_activity_json, @account.id, inbox_url]
-    end
-  end
-
   def signed_activity_json
     @signed_activity_json ||= Oj.dump(serialize_payload(@status, @status.reblog? ? ActivityPub::UndoAnnounceSerializer : ActivityPub::DeleteSerializer, signer: @account))
   end
@@ -171,10 +146,6 @@ class RemoveStatusService < BaseService
     @status.media_attachments.destroy_all
   end
 
-  def remove_from_spam_check
-    redis.zremrangebyscore("spam_check:#{@status.account_id}", @status.id, @status.id)
-  end
-
   def lock_options
     { redis: Redis.current, key: "distribute:#{@status.id}" }
   end
diff --git a/app/services/report_service.rb b/app/services/report_service.rb
index 9d9c7d6c9..bc0a8b464 100644
--- a/app/services/report_service.rb
+++ b/app/services/report_service.rb
@@ -10,6 +10,8 @@ class ReportService < BaseService
     @comment        = options.delete(:comment) || ''
     @options        = options
 
+    raise ActiveRecord::RecordNotFound if @target_account.suspended?
+
     create_report!
     notify_staff!
     forward_to_origin! if !@target_account.local? && ActiveModel::Type::Boolean.new.cast(@options[:forward])
diff --git a/app/services/suspend_account_service.rb b/app/services/suspend_account_service.rb
index 9f4da91d4..b8dc8d5e0 100644
--- a/app/services/suspend_account_service.rb
+++ b/app/services/suspend_account_service.rb
@@ -42,7 +42,13 @@ class SuspendAccountService < BaseService
   end
 
   def distribute_update_actor!
-    ActivityPub::UpdateDistributionWorker.perform_async(@account.id) if @account.local?
+    return unless @account.local?
+
+    account_reach_finder = AccountReachFinder.new(@account)
+
+    ActivityPub::DeliveryWorker.push_bulk(account_reach_finder.inboxes) do |inbox_url|
+      [signed_activity_json, @account.id, inbox_url]
+    end
   end
 
   def unmerge_from_home_timelines!
@@ -90,4 +96,8 @@ class SuspendAccountService < BaseService
       end
     end
   end
+
+  def signed_activity_json
+    @signed_activity_json ||= Oj.dump(serialize_payload(@account, ActivityPub::UpdateSerializer, signer: @account))
+  end
 end
diff --git a/app/services/unsuspend_account_service.rb b/app/services/unsuspend_account_service.rb
index ce9ee48ed..949c670aa 100644
--- a/app/services/unsuspend_account_service.rb
+++ b/app/services/unsuspend_account_service.rb
@@ -12,6 +12,7 @@ class UnsuspendAccountService < BaseService
     merge_into_home_timelines!
     merge_into_list_timelines!
     publish_media_attachments!
+    distribute_update_actor!
   end
 
   private
@@ -36,6 +37,16 @@ class UnsuspendAccountService < BaseService
     # @account would now be nil.
   end
 
+  def distribute_update_actor!
+    return unless @account.local?
+
+    account_reach_finder = AccountReachFinder.new(@account)
+
+    ActivityPub::DeliveryWorker.push_bulk(account_reach_finder.inboxes) do |inbox_url|
+      [signed_activity_json, @account.id, inbox_url]
+    end
+  end
+
   def merge_into_home_timelines!
     @account.followers_for_local_distribution.find_each do |follower|
       FeedManager.instance.merge_into_home(@account, follower)
@@ -81,4 +92,8 @@ class UnsuspendAccountService < BaseService
       end
     end
   end
+
+  def signed_activity_json
+    @signed_activity_json ||= Oj.dump(serialize_payload(@account, ActivityPub::UpdateSerializer, signer: @account))
+  end
 end
diff --git a/app/validators/blacklisted_email_validator.rb b/app/validators/blacklisted_email_validator.rb
index 1ca73fdcc..eb66ad93d 100644
--- a/app/validators/blacklisted_email_validator.rb
+++ b/app/validators/blacklisted_email_validator.rb
@@ -6,26 +6,25 @@ class BlacklistedEmailValidator < ActiveModel::Validator
 
     @email = user.email
 
-    user.errors.add(:email, :blocked) if blocked_email?
+    user.errors.add(:email, :blocked) if blocked_email_provider?
+    user.errors.add(:email, :taken) if blocked_canonical_email?
   end
 
   private
 
-  def blocked_email?
-    on_blacklist? || not_on_whitelist?
+  def blocked_email_provider?
+    disallowed_through_email_domain_block? || disallowed_through_configuration? || not_allowed_through_configuration?
   end
 
-  def on_blacklist?
-    return true  if EmailDomainBlock.block?(@email)
-    return false if Rails.configuration.x.email_domains_blacklist.blank?
-
-    domains = Rails.configuration.x.email_domains_blacklist.gsub('.', '\.')
-    regexp  = Regexp.new("@(.+\\.)?(#{domains})", true)
+  def blocked_canonical_email?
+    CanonicalEmailBlock.block?(@email)
+  end
 
-    regexp.match?(@email)
+  def disallowed_through_email_domain_block?
+    EmailDomainBlock.block?(@email)
   end
 
-  def not_on_whitelist?
+  def not_allowed_through_configuration?
     return false if Rails.configuration.x.email_domains_whitelist.blank?
 
     domains = Rails.configuration.x.email_domains_whitelist.gsub('.', '\.')
@@ -33,4 +32,13 @@ class BlacklistedEmailValidator < ActiveModel::Validator
 
     @email !~ regexp
   end
+
+  def disallowed_through_configuration?
+    return false if Rails.configuration.x.email_domains_blacklist.blank?
+
+    domains = Rails.configuration.x.email_domains_blacklist.gsub('.', '\.')
+    regexp  = Regexp.new("@(.+\\.)?(#{domains})", true)
+
+    regexp.match?(@email)
+  end
 end
diff --git a/app/views/admin/dashboard/index.html.haml b/app/views/admin/dashboard/index.html.haml
index f2f0c813d..ae5ee270e 100644
--- a/app/views/admin/dashboard/index.html.haml
+++ b/app/views/admin/dashboard/index.html.haml
@@ -79,8 +79,6 @@
           = feature_hint(link_to(t('admin.dashboard.trends'), edit_admin_settings_path), @trends_enabled)
         %li
           = feature_hint(link_to(t('admin.dashboard.feature_relay'), admin_relays_path), @relay_enabled)
-        %li
-          = feature_hint(link_to(t('admin.dashboard.feature_spam_check'), edit_admin_settings_path), @spam_check_enabled)
 
   .dashboard__widgets__versions
     %div
diff --git a/app/views/admin/follow_recommendations/_account.html.haml b/app/views/admin/follow_recommendations/_account.html.haml
new file mode 100644
index 000000000..af5a4aaf7
--- /dev/null
+++ b/app/views/admin/follow_recommendations/_account.html.haml
@@ -0,0 +1,20 @@
+.batch-table__row
+  %label.batch-table__row__select.batch-table__row__select--aligned.batch-checkbox
+    = f.check_box :account_ids, { multiple: true, include_hidden: false }, account.id
+  .batch-table__row__content.batch-table__row__content--unpadded
+    %table.accounts-table
+      %tbody
+        %tr
+          %td= account_link_to account
+          %td.accounts-table__count.optional
+            = number_to_human account.statuses_count, strip_insignificant_zeros: true
+            %small= t('accounts.posts', count: account.statuses_count).downcase
+          %td.accounts-table__count.optional
+            = number_to_human account.followers_count, strip_insignificant_zeros: true
+            %small= t('accounts.followers', count: account.followers_count).downcase
+          %td.accounts-table__count
+            - if account.last_status_at.present?
+              %time.time-ago{ datetime: account.last_status_at.to_date.iso8601, title: l(account.last_status_at.to_date) }= l account.last_status_at
+            - else
+              \-
+            %small= t('accounts.last_active')
diff --git a/app/views/admin/follow_recommendations/show.html.haml b/app/views/admin/follow_recommendations/show.html.haml
new file mode 100644
index 000000000..5b949a165
--- /dev/null
+++ b/app/views/admin/follow_recommendations/show.html.haml
@@ -0,0 +1,41 @@
+- content_for :page_title do
+  = t('admin.follow_recommendations.title')
+
+- content_for :header_tags do
+  = javascript_pack_tag 'admin', async: true, crossorigin: 'anonymous'
+
+%p= t('admin.follow_recommendations.description_html')
+
+%hr.spacer/
+
+= form_tag admin_follow_recommendations_path, method: 'GET', class: 'simple_form' do
+  .filters
+    .filter-subset.filter-subset--with-select
+      %strong= t('admin.follow_recommendations.language')
+      .input.select.optional
+        = select_tag :language, options_for_select(I18n.available_locales.map { |key| [human_locale(key), key]}, @language)
+
+    .filter-subset
+      %strong= t('admin.follow_recommendations.status')
+      %ul
+        %li= filter_link_to t('admin.accounts.moderation.active'), status: nil
+        %li= filter_link_to t('admin.follow_recommendations.suppressed'), status: 'suppressed'
+
+= form_for(@form, url: admin_follow_recommendations_path, method: :patch) do |f|
+  - RelationshipFilter::KEYS.each do |key|
+    = hidden_field_tag key, params[key] if params[key].present?
+
+  .batch-table
+    .batch-table__toolbar
+      %label.batch-table__toolbar__select.batch-checkbox-all
+        = check_box_tag :batch_checkbox_all, nil, false
+      .batch-table__toolbar__actions
+        - if params[:status].blank? && can?(:suppress, :follow_recommendation)
+          = f.button safe_join([fa_icon('times'), t('admin.follow_recommendations.suppress')]), name: :suppress, class: 'table-action-link', type: :submit, data: { confirm: t('admin.reports.are_you_sure') }
+        - if params[:status] == 'suppressed' && can?(:unsuppress, :follow_recommendation)
+          = f.button safe_join([fa_icon('plus'), t('admin.follow_recommendations.unsuppress')]), name: :unsuppress, class: 'table-action-link', type: :submit
+    .batch-table__body
+      - if @accounts.empty?
+        = nothing_here 'nothing-here--under-tabs'
+      - else
+        = render partial: 'account', collection: @accounts, locals: { f: f }
diff --git a/app/views/admin/rules/index.html.haml b/app/views/admin/rules/index.html.haml
index 3b069d083..4fb993ad0 100644
--- a/app/views/admin/rules/index.html.haml
+++ b/app/views/admin/rules/index.html.haml
@@ -1,8 +1,9 @@
 - content_for :page_title do
   = t('admin.rules.title')
 
-.simple_form
-  %p.hint= t('admin.rules.description')
+%p= t('admin.rules.description_html')
+
+%hr.spacer/
 
 - if can? :create, :rule
   = simple_form_for @rule, url: admin_rules_path do |f|
diff --git a/app/views/admin/settings/edit.html.haml b/app/views/admin/settings/edit.html.haml
index fa8d8441e..1fab9dd06 100644
--- a/app/views/admin/settings/edit.html.haml
+++ b/app/views/admin/settings/edit.html.haml
@@ -101,9 +101,6 @@
   .fields-group
     = f.input :show_replies_in_public_timelines, as: :boolean, wrapper: :with_label, label: t('admin.settings.show_replies_in_public_timelines.title'), hint: t('admin.settings.show_replies_in_public_timelines.desc_html')
 
-  .fields-group
-    = f.input :spam_check_enabled, as: :boolean, wrapper: :with_label, label: t('admin.settings.spam_check_enabled.title'), hint: t('admin.settings.spam_check_enabled.desc_html')
-
   %hr.spacer/
 
   .fields-group
diff --git a/app/views/user_mailer/webauthn_enabled.text.erb b/app/views/user_mailer/webauthn_enabled.text.erb
index 4c233fefb..d4482a69b 100644
--- a/app/views/user_mailer/webauthn_enabled.text.erb
+++ b/app/views/user_mailer/webauthn_enabled.text.erb
@@ -1,7 +1,7 @@
-<%= t 'devise.mailer.webauthn_credentia.added.title' %>
+<%= t 'devise.mailer.webauthn_credential.added.title' %>
 
 ===
 
-<%= t 'devise.mailer.webauthn_credentia.added.explanation' %>
+<%= t 'devise.mailer.webauthn_credential.added.explanation' %>
 
 => <%= edit_user_registration_url %>
diff --git a/app/workers/scheduler/follow_recommendations_scheduler.rb b/app/workers/scheduler/follow_recommendations_scheduler.rb
new file mode 100644
index 000000000..0a0286496
--- /dev/null
+++ b/app/workers/scheduler/follow_recommendations_scheduler.rb
@@ -0,0 +1,61 @@
+# frozen_string_literal: true
+
+class Scheduler::FollowRecommendationsScheduler
+  include Sidekiq::Worker
+  include Redisable
+
+  sidekiq_options retry: 0
+
+  # The maximum number of accounts that can be requested in one page from the
+  # API is 80, and the suggestions API does not allow pagination. This number
+  # leaves some room for accounts being filtered during live access
+  SET_SIZE = 100
+
+  def perform
+    # Maintaining a materialized view speeds-up subsequent queries significantly
+    AccountSummary.refresh
+
+    fallback_recommendations = FollowRecommendation.safe.filtered.limit(SET_SIZE).index_by(&:account_id)
+
+    I18n.available_locales.each do |locale|
+      recommendations = begin
+        if AccountSummary.safe.filtered.localized(locale).exists? # We can skip the work if no accounts with that language exist
+          FollowRecommendation.safe.filtered.localized(locale).limit(SET_SIZE).index_by(&:account_id)
+        else
+          {}
+        end
+      end
+
+      # Use language-agnostic results if there are not enough language-specific ones
+      missing = SET_SIZE - recommendations.keys.size
+
+      if missing.positive?
+        added = 0
+
+        # Avoid duplicate results
+        fallback_recommendations.each_value do |recommendation|
+          next if recommendations.key?(recommendation.account_id)
+
+          recommendations[recommendation.account_id] = recommendation
+          added += 1
+
+          break if added >= missing
+        end
+      end
+
+      redis.pipelined do
+        redis.del(key(locale))
+
+        recommendations.each_value do |recommendation|
+          redis.zadd(key(locale), recommendation.rank, recommendation.account_id)
+        end
+      end
+    end
+  end
+
+  private
+
+  def key(locale)
+    "follow_recommendations:#{locale}"
+  end
+end
diff --git a/app/workers/web/push_notification_worker.rb b/app/workers/web/push_notification_worker.rb
index 46aeaa30b..57f5b5c22 100644
--- a/app/workers/web/push_notification_worker.rb
+++ b/app/workers/web/push_notification_worker.rb
@@ -3,22 +3,67 @@
 class Web::PushNotificationWorker
   include Sidekiq::Worker
 
-  sidekiq_options backtrace: true, retry: 5
+  sidekiq_options queue: 'push', retry: 5
+
+  TTL     = 48.hours.to_s
+  URGENCY = 'normal'
 
   def perform(subscription_id, notification_id)
-    subscription = ::Web::PushSubscription.find(subscription_id)
-    notification = Notification.find(notification_id)
+    @subscription = Web::PushSubscription.find(subscription_id)
+    @notification = Notification.find(notification_id)
+
+    # Polymorphically associated activity could have been deleted
+    # in the meantime, so we have to double-check before proceeding
+    return unless @notification.activity.present? && @subscription.pushable?(@notification)
+
+    payload = @subscription.encrypt(push_notification_json)
 
-    subscription.push(notification) unless notification.activity.nil?
-  rescue Webpush::ResponseError => e
-    code = e.response.code.to_i
+    request_pool.with(@subscription.audience) do |http_client|
+      request = Request.new(:post, @subscription.endpoint, body: payload.fetch(:ciphertext), http_client: http_client)
 
-    if (400..499).cover?(code) && ![408, 429].include?(code)
-      subscription.destroy!
-    else
-      raise e
+      request.add_headers(
+        'Content-Type'     => 'application/octet-stream',
+        'Ttl'              => TTL,
+        'Urgency'          => URGENCY,
+        'Content-Encoding' => 'aesgcm',
+        'Encryption'       => "salt=#{Webpush.encode64(payload.fetch(:salt)).delete('=')}",
+        'Crypto-Key'       => "dh=#{Webpush.encode64(payload.fetch(:server_public_key)).delete('=')};#{@subscription.crypto_key_header}",
+        'Authorization'    => @subscription.authorization_header
+      )
+
+      request.perform do |response|
+        # If the server responds with an error in the 4xx range
+        # that isn't about rate-limiting or timeouts, we can
+        # assume that the subscription is invalid or expired
+        # and must be removed
+
+        if (400..499).cover?(response.code) && ![408, 429].include?(response.code)
+          @subscription.destroy!
+        elsif !(200...300).cover?(response.code)
+          raise Mastodon::UnexpectedResponseError, response
+        end
+      end
     end
   rescue ActiveRecord::RecordNotFound
     true
   end
+
+  private
+
+  def push_notification_json
+    json = I18n.with_locale(@subscription.locale || I18n.default_locale) do
+      ActiveModelSerializers::SerializableResource.new(
+        @notification,
+        serializer: Web::NotificationSerializer,
+        scope: @subscription,
+        scope_name: :current_push_subscription
+      ).as_json
+    end
+
+    Oj.dump(json)
+  end
+
+  def request_pool
+    RequestPool.current
+  end
 end