550 REJECTED - Bad HELO - Host impersonating


Active Member
Jan 18, 2007
Hi Guys,

I am getting emails rejected back to our server with the following error:

SMTP error from remote mail server after MAIL FROM:<**********> SIZE=1741:
host mail.hypernia.com []: 550 "REJECTED - Bad HELO - Host impersonating [**********]"
We recently moved our web server from one box to another due to hardware failure on the old machine during the migration we kept the same hostname and in turn we updated DNS, nameservers & rDNS to point to the new machine.

After about two weeks of waiting we are still getting the above rejection email when we attempt to send email other cpanel based machines (well is appears to be mainly cpanel machines).

I can send email to hotmail, gmail and yahoo without issue, but to another cpanel machine i get the above.

I know i can remove the ACL on the remote cpanel host, however I am trying to track down why it thinks the machine is impersonating the old machine.

Any ideas where to look, I cannot figure it out.

(We did change IPs)