fdqn hostname problem

I got a strange problem which I have been unable to resolve.

I have 2 servers.
* the first, server1.mydomain.com, runs an older fedora installation with qmail and plesk.
* the second, server2.mydomain.com runs brand new debian 5 with postfix and ISPconfig 3.

When I try to send emails from an address on server1 to an address on server2, the email gets rejected by postfix on server2 because of the policy "REJECT non_fdqn_hostname".

Now, I am puzzled as to why the hostname of server1 is non-fdqn.
The server sends a proper helo with server1.mydomain.com

Could someone please walk me through some steps to diagnose the problem?

Thank you

 

maybe you need PTR record for you serves?

 

PTR has been set years ago

 

ok, more strange even:

when I deactivate the reject non_fdqn_hostname policy in postfix, the mail still gets rejected because of the reject non_fdqn_sender policy ??

how can a sender be non-fdqn?

 

solved, I guess:

reject non_fdqn_* will cause everything to be rejected, because the correct spelling of the policy is non_fqdn_*