AFAICT, there is no way in which Phabricator or Gmail can tell me whether "I am being mentioned in a certain task" vs "I was already among the subscribers", right? Looks like other colleagues of mine would really appreciate being able to tell whether someone is actively calling for our attention, maybe even help, and hence having a certain priority, vs "this is the nth task I get just because I'm subscribed to a topic for which my interest may vary", which may or may not be read (my Phab folder has 18k unread messages and counting).
List of open tasks mentioned below:
* https://secure.phabricator.com/T9031 "When I ignore subscription changes, I'm not notified of being cc'ed"
* https://secure.phabricator.com/T9412 "Annotate all the reasons that a user is included on the recipient list for mail"
* https://secure.phabricator.com/T4654 "Add 'always email me' type option for direct mentions, ccs, assignments, etc"
List of closed tasks mentioned below, with relevant discussion points:
* https://secure.phabricator.com/T9161 "How can we fix "too much mail"?"
* https://secure.phabricator.com/T6297#88557 "Maniphest email notification doesn't say why I'm receiving it" - a custom mail header could include an additional "User has been mentioned when this comment got added" value.