Basic Authentication Deprecation in Exchange Online – September 2022 Update

Greg Taylor - EXCHANGE I think part of the confusion comes from the fact that the terms "smtp auth", "basic auth", and "smtp basic auth" have been thrown around a lot. I have spent 2 days reading through the documentation and different forums and the only clear cut answer I have seen about this is your answer: 

We are not disabling basic auth for SMTP. You can keep using after Oct 1st, Jan 1st, pick whatever date you want. That might change one day, but there's no date for it yet.

Our issue is that we are distributing a single tenancy monolith where customers can freely choose their own email provider, we just provide a simple form with username/password/host/port and they can choose whatever they want to send emails from our application. But thanks for the clear answer, I expect this functionality to continue to work until further notice down the road.