> Update 1 - I know I can simply change the MX record to someone else but It has its own challenges.
I don't quite get that attitude. He's describing that he needs his business emails. Not just getting a mail server back online for that, even as interim solution, points to the opposite. In the time it takes for MX TTL to expire he could easily just throw up a postfix+dovecot on some VPS, with enough time to spare to add something like sogo if he feels fancy.