Change e-mail notifications to only be sent when recipient is offline (#17984)

* Change e-mail notifications to only be sent when recipient is offline

Change the default for follow and mention notifications back on

* Add preference to always send e-mail notifications

* Change wording

config/locales/simple_form.en.yml

@@ -49,6 +49,7 @@ en:
         phrase: Will be matched regardless of casing in text or content warning of a post
         scopes: Which APIs the application will be allowed to access. If you select a top-level scope, you don't need to select individual ones.
         setting_aggregate_reblogs: Do not show new boosts for posts that have been recently boosted (only affects newly-received boosts)
+        setting_always_send_emails: Normally e-mail notifications won't be sent when you are actively using Mastodon
         setting_default_sensitive: Sensitive media is hidden by default and can be revealed with a click
         setting_display_media_default: Hide media marked as sensitive
         setting_display_media_hide_all: Always hide media
@@ -151,6 +152,7 @@ en:
         phrase: Keyword or phrase
         setting_advanced_layout: Enable advanced web interface
         setting_aggregate_reblogs: Group boosts in timelines
+        setting_always_send_emails: Always send e-mail notifications
         setting_auto_play_gif: Auto-play animated GIFs
         setting_boost_modal: Show confirmation dialog before boosting
         setting_crop_images: Crop images in non-expanded posts to 16x9

config/settings.yml

@@ -38,16 +38,17 @@ defaults: &defaults
   trendable_by_default: false
   crop_images: true
   notification_emails:
-    follow: false
+    follow: true
     reblog: false
     favourite: false
-    mention: false
+    mention: true
     follow_request: true
     digest: true
     report: true
     pending_account: true
     trending_tag: true
     appeal: true
+  always_send_emails: false
   interactions:
     must_be_follower: false
     must_be_following: false