Hi
It would appear though the initial email address I used to create an account was accepted, the confirmation email was never sent. Not sure if you can see it in an audit log or I can send it in PM. What makes me think it’s a bug is it was a temporary email, the account creation blocked one domain but allowed another.
I use temporary /disposable addresses because hacks happen.
Not really a bug as this was intentional by design. But I’ll ping the right group to get you taken care of.
Did you just get an email asking for you to reactivate your account?
To my existing email address yes, and was logged out of the site. Nothing to the original temp email though.
Think there is a bit of misunderstanding here mostly because I don’t want to post the email addresses in public at least. There is only one account, I tried three different email addresses including the one now associated with it. The first one was rejected at setup, the second was accepted but I never received a confirmation email. The third and current one was accepted and I received a confirmation email to.
Ah OK that’s fine then. Likely your email servers were bad for the second address.
Mail server is fine, more likely amazon^Wyour provider blocked it outbound 
If you use mailgun like most Discourse sites and don’t pay for a dedicated IP, you sometimes get outgoing mail blocked. Need to login to Mailgun and check it out, then if so open a support request asking them to move your account to a different IP.