Been awhile since I looked at this but seems to me I was able to do something in voicemail admin settings. I believe it was the “From”: string that I was able to change. Sounds like you want to change the actual from username which is different. There is also the serveremail=vm@asterisk setting but I don’t remember what that changed. I don’t think either of those will do what you want though.
So there was a road map to abstract all email to framework. The plumbing was put in to 15 and in 16 we were going to unify and standardize email. That said the “WE” who had this roadmap had left the dev team before 16 was planned out. Much of the 16 focus went to migration from zendguard to ioncube so people could use php 7.4. The migration couldn’t happen until the commercial products could use it. I haven’t seen one word about the future of FreePBX unfortunately. The dev team has been generally reduced to the team in Bangalore. The Sangoma CEO was just unceremoniously ousted which as a shareholder I think was long over due. That said the Star2Star guy is in charge now and I wouldn’t be surprised if that portfolio of products gets more attention. There is going to be a big push to consolidate the countless redundancies in the product line and anything that makes money will get priority. In general we are in wait and see mode.
Currently the way email is setup in most places it does a check… if there is a from address in whatever place it wants it then use that, otherwise use user @ hostname which is why that is a common default.
I have never opened a ticket that resulted in anything getting fixed. In over a decade. I don’t waste the time any longer; doing the same thing over and over and expecting a different outcome is insane.
Unfortunately, I fully agree with you on this one and I wish that wasn’t the case.
Over the years we implemented our own scripts to setup postfix with our SMTP gateway, a script that replaces PagePro’s scheduled pages (we also wrote a small NodeJS library that makes exclusions very easy, such as holidays etc.) etc etc etc.