[There are numerous similar questions on ServerFault but I couldn't find one that was exactly on point]

Background: I use Gmail for my email client. My email is [email protected]. However the email that people communicate to me with is [email protected]. I run the server that hosts www.example.com and other domains, at ServerBeach.

Up to yesterday, I had SENDMAIL painlessly just forward emails to [email protected] to [email protected] and everything was fine, for several years in fact.

Suddenly my email stopped working - that is, my gmail account stopped receiving emails via the forward from my server.

Looking into it I found a bunch of emails sitting on my server with content like this:

... while talking to gmail-smtp-in.l.google.com.:

RCPT To: <<< 450-4.2.1 The user you are trying to contact is receiving mail at a rate that <<< 450-4.2.1 prevents additional messages from being delivered. Please resend your <<< 450-4.2.1 message at a later time. If the user is able to receive mail at that <<< 450-4.2.1 time, your message will be delivered. For more information, please <<< 450 4.2.1 visit xxxxxx://mail.google.com/support/bin/answer.py?answer=6592 u15si37138086qco.76 [email protected]... Deferred: 450-4.2.1 The user you are trying to contact is receiving mail at a rate that DATA <<< 550-5.7.1 [64.34.168.137 1] Our system has detected an unusual rate of <<< 550-5.7.1 unsolicited mail originating from your IP address. To protect our <<< 550-5.7.1 users from spam, mail sent from your IP address has been blocked. <<< 550-5.7.1 Please visit xxxxx://www.google.com/mail/help/bulk_mail.html to review <<< 550 5.7.1 our Bulk Email Senders Guidelines. u15si37138086qco.76 554 5.0.0 Service unavailable ... while talking to alt1.gmail-smtp-in.l.google.com.:

From what I've been researching, I think somehow someone has/is hijacking my domain name or something and this somehow has caused gmail's servers to notice and cut me off. But I don't know really what's going on nor do I see whatever emails might be involved.

I've read stuff on zoneedit.com that sounds like they might have a solution in their service for what I am trying to do. I also read a lot about admining DNS and SENDMAIL and tried various things, but nothing works.

1. Can you tell from my description what is going on that caused GMail's server to stop accepting email from my server and is there a way to stop it?
2. What is the 'correct' way to configure things so that emails to [email protected] behave as if they were sent to [email protected]?

Thanks so much!