You have the option of using a smart host. You can read a brief description here: http://en.wikipedia.org/wiki/S... Some have a free tier, some don't. I've usually use a smarthost by default so that my smtp server's IP address is not directly associated with the message by default and instead I can opt to bypass the smarthost if the smarthost gets blocked for any reason. Here is one that I found but have never used: http://www.socketlabs.com/sign...