I checked my email last night and it was fine, but today when I checked it my last email was from last night. I tried to shoot an email to myself from AOL and get a "user known" error.

----- The following addresses had permanent fatal errors -----
<rob@domain>

----- Transcript of session follows -----
... while talking to domain.:
>>> RCPT To:<rob@domain>
<<< 550-Callback setup failed while verifying <Irishguy@aim.com>
<<< 550-(result of an earlier callout reused).
<<< 550-The initial connection, or a HELO or MAIL FROM:<> command was
<<< 550-rejected. Refusing MAIL FROM:<> does not help fight spam, disregards
<<< 550-RFC requirements, and stops you from receiving standard bounce
<<< 550-messages. This host does not accept mail from domains whose servers
<<< 550-refuse bounces.
<<< 550 Sender verify failed
550 <rob@domain>... User unknown
I can email myself from my server and have got a couple of spam mails. Maybe this is due to an automatic update or something? I haven't been online or changed anything since last night.

Any ideas?