Security problem with Discourse emails?

@blake, @Vimala

A few days ago, we changed the email address for the default emails sent by Discourse, so it now has suttacentraldev as the sender. So that’s fine, but it seems that at the same time, my protonmail started giving me security warnings:

This email has failed its domain’s authentication requirements. It may be spoofed or improperly forwarded!

Now i doubt if there’s any actual problem, but still, we should not be triggering warnings. I’m wondering if gmail gives a similar warning? Is there anything that can be done about it?

Gmail does not give such a warning. I suspect the problem has to do with being a gmail address, which can be set up by anybody and not an address on a dedicated domain like or so.