I still have problems when I try send mail to some mailservers (eg.
hotel@karolina.lt ) I got:

Transcript of session follows:
MAIL FROM:<dstragowski@jzo.com.pl>
553 5.1.8 <dstragowski@jzo.com.pl>... Domain of sender address
dstragowski@jzo.com.pl does not exist

I my DNS all seems OK (I test it by www.dnsreport.com).

My mailserver (GroupWise 6) is behind Norton Antivirus for GateWays

Best regards,