Hi!
Ok
Have you tried setting the From Address in Notification Settings to [email protected]?
Does your firewall permits your PBX to talk to Microsoft’s servers?
Using the SMTP submission port? (port 587)
Looking at the IP address of office365.com servers I see that it tries to use IPV6, is this properly setted up on your network/firewall?
If not, you might want to disable it on your FreePBX box, see How to disable IPV6 [SOLVED]
Good luck and have a nice day!
Nick