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 rejection. 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: www.merit.edu/mn/support/reversedns.html Please send any questions to nanog-support@nanog.org .