Both the queue processor and ScheduledJob emails need to sometimes pass a
to_user_id and sometimes pass a to_email, and it's more convenient to just
have one function that they can call that can handle either.
Also removes the now redundant send_email_to_user.
Previously, we were checking for "Zulip" entries in User-Agent strings
at the very end of the list, not the beginning. A Zulip User-Agent
should have priority, since it includes the User-Agent strings for a
lot of other browsers, and also it will always be the most specific
value.
This commit replaces all uses of django.core.mail.send_mail with send_email,
other than in the password reset flow, since that code looks like it is just
a patch to Django's password reset code.
The send_email function is in a new file, since putting it in
zerver.lib.notifications would create an import loop with confirmation.models.
send_future_email will soon be moved into email.py as well.
This adds helpful email notifications for users who just logged into a
Zulip server, as a security protection against accounts being hacked.
Text tweaked by tabbott.
Fixes#2182.
Rishi Gupta
James Rowan
Tim Abbott
neiljp (Neil Pilgrim)
Umair Khan
hackerkid
hollywoodno