No access to Bellsouth.net email.

For over a week I have been unable to send or receive email on my Bellsouth.net account. It stopped working on my desktop client (Outlook) and my iPhone on the same day. If I send an email to it via a gMail account it comes back 'address not found or unable to receive mail'. I managed to speak to a rep a few days ago that said he would investigate but so far nothing. I have changed my ATT password but still nothing. If I go through your Currently portal, my mail login redirects to your ATT mail help page. What is going on?? Have you migrated mail servers and lost some links?? This address has been in use for over 20 years and now I have contacts that keep getting bounce back error messages when they send something. What is your solution?