PAN-OS does not support this configuration as of today.
In order to work around this, I built a small Ubuntu virtual machine and installed Dovecot and Postfix. With this in place, I can have my PA-500 e-mail reports through this "relay server", which then hands it off to gmail using SSL/TLS/Authentication, etc.
Unfortunately, I don't have specific instructions on how I built the relay server - but I remember it didn't take too long after googling for some how-to docs.
Click Accept as Solution to acknowledge that the answer to your question has been provided.
The button appears next to the replies on topics you’ve started. The member who gave the solution and all future visitors to this topic will appreciate it!
These simple actions take just seconds of your time, but go a long way in showing appreciation for community members and the LIVEcommunity as a whole!
The LIVEcommunity thanks you for your participation!