Password reset email should use first identity domain if available

[TkTech]

The email templates for account_new.html and password_reset.html are hardcoded to use MAIN_DOMAIN instead of the current request domain.

[andrewgodwin]

Yes, because they are sent from background workers rather than a view. MAIN_DOMAIN is going to have to be something that everyone uses for those links, at minimum, even if we redirect them to the service domain after login.

[TkTech]

Ah, I had a PR for this. I was using the domain from the user's first identity which I was considering the "default". Essentially, I'm "white labeling" this for family and friends, and I don't want the emails to send them to @tkte.ch instead of @gowoon.ca.

[andrewgodwin]

Hmm, interesting - I had presumed that new accounts would not have an identity yet, so the Create Account email would have to go to MAIN_DOMAIN. You're right though, password resets could try their first identity.

[TkTech]

Yeah, the process right now is to create the domain, create a user, add an identity, then send them a password reset (since invites aren't there just yet)

[gwagstaff]

Grabbing this issue + taking the chance to spruce up the email templates with html