Same, ran very (technically speaking) clean MiAB setup for local business and after 2 years we had to drop it due to delivery issues with MS business accounts.

Same, ran very (technically speaking) clean MiAB setup for local business and after 2 years we had to drop it due to delivery issues with MS business accounts. Invoices missed, etc. - a royal pain in the arse. Only a full migration to gmail biz domain fixed things fully. Email. Yikes.