I verified the short-code change by doing it myself. Now, there’s no map at all (not ideal but not necessarily a problem). In spite of that change, the outgoing mails for some customers were still failing. I just got off the phone with inMotion and they said they have Span Assassin as a gate-keeper on outgoing email. Turns out that THAT is the issue! They turned it off and everything goes out as it should.
Since this is resolved, did we consume the support token?