Hydra notification emails get auto-junked by gmail

[copumpkin]

This appears to be because Hydra claims all emails come from edolstra@gmail.com, so gmail knows with certainty that it's spoofed. You can set up a filter to stop them from going to spam, but it will always add the spoofing notice to the top of the email.

I'd just set up some sort of hydra-noreply@nixos.org to avoid this problem, since the sender address doesn't really add much value here.

[domenkozar]

Also see https://github.com/NixOS/hydra/pull/264

[copumpkin]

cc @edolstra