When someone does an action (e.g. adds a comment), Phabricator sends an email with sender set to
[username] <no-reply@phabricator.wikimedia.org>
`[username]` changes but the rest doesn't; this confuses mail clients into thinking all mails are from the same person. This is how an opened Phabricator thread looks in Gmail:
{F19931}
This is how a thread looks in the thread list:
{F19935}
Note how all messages appear to come from the person who opened the bug. This makes it very hard to search or browse email notifications, especially when there are mass changes. (For example, a bot just created a hundred multimedia tickets; I would really like to see which ones have human activity, and Gmail is normally great at showing these things in the thread list view, by displaying the senders of all the unread messages in the thread:
{F19948}
but here that's broken by Phabricator's use of the same email address for all senders.
Ideally, email addresses in the From: field would look like
[username] <no-reply-[userid]@phabricator.wikimedia.org>
or something along those lines.