facebook/phabricator — pull request #435 by r4nt (2013-11-09 02:25:05+00:00)
Title: Make send-as-user more robust.

Add a List-Id field when sending as a user. Spam filters assume that something
is not a mailing list if it doesn't set the List-Id header, so we need to set
it when we pretend to be a mailing list.
Also, set the correct user name when sending as a user.