problems with email

[passtheword]

I am currently experiencing issues with sending email on my acct. I discovered this after I attempted to send myself a copy of an email  (using the same email address), and I received a bounce back message. This has never happened before in the past when I have forwarded myself an email. I have now noted that whenever I send emails to other address with that same "from" email address, those emails do not arrive to the recipients, either. Sometimes I receive a bounce back message, which is the following:


Permanent Failure:554 REPLY: 554_mail_server_permanently_rejected_message_(#5.3.0)
       Delivery last attempted at Sun,  3 Mar 2013 18:47:04 -0000

Final-Recipient: rfc822; Action: failed
Status: 5.1.0
Diagnostic-Code: smtp; (Permanent Failure: Other address status)
Last-Attempt-Date: Sun,  3 Mar 2013 18:47:04 -0000


I am able to receive email as usual on all domains (in the same plesk acct). The error seems to only affect one particular domain in my acct (qezradio.com); the other domains can send/receive email as usual.

I usually use an email program to send out my email, so I opened the webmail for the domain above to see if the same problems occurred there as well. I noticed that it was using atmail rather than horde, as all the other domains in my acct are using (and have used in the past).