Smtp timeout with custom domain

Hello, I recently attempted switching to a custom domain but (hastily) bailed on it because the app wasn't sending emails properly. This is typically what I would get:

smtplib.SMTPResponseException: (451, b'4.4.2 Timeout - closing connection. l66sm16594711qte.48 - gsmtp')

I went back to using "" for my website and the proper handing of emails was restored.

Was I too hasty? What might be the cause of the difference between the two settings? If it helps, I was using NameCheap for my custom domain. (My custom domain worked perfectly aside from this issue with email.)


If the email address you're sending from is somehow based on the site name, that could affect whether the email is sent correctly. Otherwise it may be that you broke something when you changed the site name. Check that the settings that you are using for the email sending are correct at the point in the code where you send the email.