550 5.2.1 ... blank mailhost - invalid address, relay=[209.85.166.172]

We're here to help @JKlajones, with sending emails.

• Have you check to make sure that your server settings are correct?
• How are you accessing your emails?
• Have you trying signing in at http://sm.att.com/e05b5109 to see if you can send emails there?
• We would also suggest that you try changing the password to sync your account.
• Resolve email issues

Please let us know so we can better assist you.

Charles, AT&T Community Specialist

I have the same issue.  I have tried everything and still can't receive emails.  I can send but can't receive. 

Same thing, not receiving any email at my bellsouth.net account.  However I can send out email.  I tested this by sending an email from my bellsouth account to a non bellsouth account. It was delivered ok.  I then clicked reply to send the email back to my bellsouth account and got it returned as undeliverable with this message "blank mailhost - invalid address, relay=[66.163.185.148]"