Ensure the server is sending (and receiving) emails, for the purposes of authentication.
Refer to https://secure.phabricator.com/book/phabricator/article/configuring_outbound_email/ and Technical
Description
Description
Event Timeline
Comment Actions
Emails seem to be successfully delivering now, with Ziggy's assistance in setting up mail for the server, and configuration of Phabricator to talk to the smtp server.
I have also changed the global default settings to disable Self-Action mail notifications by default. It seems superfluous to receive emails notifying of actions that the user did.
Comment Actions
Apparently the email server has stopped working, potentially since the migration, so this needs to be fixed again.