Client host rejected: cannot find your hostname stop a lot of spam but also some "good guys"
Posted on 2011-02-24
How do you handle all of theese email servers for real companies which does not have a reverse lookup for their IP ?
We check all incoming email to our server and too many "wanted" emails are bounced due to this ("Client host rejected: cannot find your hostname")
Email server with Ubuntu Linux and Postfix.
Accordning to official RFC:s all email servers sending mail should have a reverse lookup and preferably also the same forward lookup for that IP.
I know we can make a list of the IP-numbers we want to let throw, and we do whenever we find any rejected email that we would have wanted, but with many customers this is too manually to be good.
How do you handle this delicate problem?