I changed from Newton when they forced use of a Newton cloud account (not to mention a new annual cost that only makes sense for businesses). Happy with this as an alternative. Extremely customizable - takes a while to get the hang of and still have a few things to sort out, but it has my top priorities: password and multiple accounts. And the team are very responsive to questions.
Prattlecette about AltaMail Classic, v5.8.2