Is this live? I was going to tell my leaders about custom mailing lists that I created, but perhaps I should delete them, and create mailboxes instead??? I have not enabled mailboxes yet, but am willing to do so if it’s reliable.
Check out this thread about the Inbox Beta Feature. It has been in beta for over two years and there was some initial discussion on the thread about some problems that @dave fixed.
https://community.trooptrack.com/t/email-inbox-subdomain-emails/4853
I had not previously enabled the Inbox Beta feature and did so just now. I did an initial test and was able to create an Inbox (Mailbox) test@unit.trooptrack.email, added myself and one other person as members, then sent a message to that address from a non TT registered e-mail address, my work account, and did get the message to my User registered e-mail as well as in the Inbox within TT.