On the mail thing - it depends on what mail program is in use on the RasPBX distro. We use a Sendmail clone that sets up the mail sending stuff pretty easily. It seems to me that RasPBX does the same. Unfortunately, setting up Email is it’s own set of dark magic, including SPAM filtering, allowed hosts to connect to servers, and firewall issues. You’re going to need to look at the logs (both mail and Asterisk …/full) in order to hope to start to figure out your specific situation.
No longer applies as access to the email server settings are now only in the Commercial Module.
For anyone experiencing similar issues that I have encountered with the Raspberry Pi version of FreePBX this article was the ONLY source of information the successfully and easily resolved the issue while others failed.