I want to thank you for your expertise in all issues in these forums. I have searched for similar issues, but couldn't find one that helped. Have tried all I know. I am running ubuntu dapper drake set up using the perfect setup. Only change was to add another IP address to the system. Installed ISPConfig and am up and running with minimal email. I have configured DNS so I am authoritative for my domain, imaple.net. When users email AOL addresses (of all things), mail is rejected, with this in mail.log: Dec 12 07:24:36 mr01 postfix/smtp: 1C58A1C5951: to=<[email protected]http://postmaster.info.aol.com/errors/554rlych.html 554 TRANSACTION FAILED (in reply to end of DATA command)) AOL reverse DNS tool says: Reverse No PTR but got: 18.104.22.168.in-addr.arpa. 172800 IN CNAME 194.192/22.214.171.124.in-addr.arpa. I'm sure it's something easy, but can't figure out what I am missing. Thanx for the help.