Thanks for the idea! I've added a test for PTR: https://github.com/JoshData/mail...

haroldp · on April 23, 2014

You might also:

* Test/alert if your PTR mismatches your HELO name

* If your IP is on any of the major RBLs

* Point admins toward AOL/Yahoo/ReturnPath whitelists and feedback loops.

btgeekboy · on April 24, 2014

Additionally, you should test whether your PTR "smells" dynamic (i.e. contains part of your IP address in the PTR itself.) It may or may not be something within your control, but you should know as it may cause you problems later.