> 554 Client host rejected: Matching Reverse and Forward Lookup Failed -
reverse query: PTR query for IP a.b.c.d returns label.domain.tld
forward query: query for the A record for label.domain.tld must return a.b.c.d
ie, having a PTR is NOT sufficient. There MUST be a matching A record.
Reason? Anybody can forge mx1.aol.com as his PTR hostname in his reverse zone file.
The forgery is uncovered when the A record for mx1. aol.com, from AOL's zone file, doesn't match the forger's IP.
Len
_____________________________________________________________________ http://IMGate.MEIway.com : free anti-spam gateway, runs on 1000's of sites
To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
