New reverse DNS filter at Merit

Greetings - I wanted to let you know that in an effort to reduce spam,
Merit will implement reverse DNS checking on incoming mail on Monday,
March 29. This means that if your IP address doesn't match the DNS zone
information for your domain name, or if your IP address can't be verified
because an IN.ADDR.ARPA file for your address block doesn't exist, the
lookup will fail and your mail will be (eek) rejected. If this happens,
you'll receive a custom message from Merit outlining the reason for the

Merit is making the change to comply with RFCs 1123 and 1912. You'll find
more info about reverse DNS checking, plus a tool you can use to check
your site's IP addresses and DNS records here:

Please send any questions to .