Question : Exchange PTR Record and Natting

If you nat your exchange outound, it seems some mail systems blacklist email even with a .ptr record.  Does anyone know the best way to set up this for both security and to help prevent blacklisting?

Answer : Exchange PTR Record and Natting

You need to have a rDNS record configured on the public facing IP address otherwise the rDNS lookup will fail.

Ideally this should match the A record your MX record points to. Have a look at my article here: http://www.experts-exchange.com/Software/Server_Software/Email_Servers/Exchange/A_2370-Exchange-DNS-Configuration.html