Start with discovery, not configuration
Build an inventory of every device, application, mailbox, sender, recipient scope, and owner before changing authentication. Unknown dependencies create the most disruptive migration failures.
Choose the right replacement per client
Use native OAuth or Microsoft Graph where supported. Evaluate Microsoft relay and other Microsoft sending methods for suitable environments. Use smtpify365 only where the client is limited to authenticated SMTP and meets its compatibility requirements.
Test the real workflow
A connection test proves only part of the path. Trigger a real scan, order, backup, alert, or password reset, then verify Microsoft processing and final receipt.