I have SIP trunking (no FXO). I realize it's not very reliable for faxing, but I still would like to give it a shot.
Under Telephony > Call handling > T.37 Fax to Mail, it's enabled. Under Mailboxes it says:
"Mailboxes with the extension configured as a destination or internal number for
an Incoming Dial Plan on a PSTN trunk are available to be selected."
When I click Add, I don't have any "available mailboxes listed". I do have a bunch of Incoming SIP Trunking DIDs configured pointing to individual extensions.
What am I missing? Is it only supported for FXO/PRI?