SMTP Modern Authentication Migration

As part of the ongoing security enhancements, Basic Authentication for SMTP Client Submission in Exchange Online (Office 365) will be permanently disabled by Microsoft, effective March 1, 2026.

If your organization currently uses Basic Authentication to send emails via Office 365, you must transition to a modern authentication method or an alternative solution before March 1, 2026, to avoid disruption.

Please note that this is a mandatory change from Microsoft and cannot be postponed or overridden by Unit4. Systems or applications that continue to use Microsoft Office 365 Basic Authentication will no longer be able to send emails after this date.

For official Microsoft information, visit: Exchange Online to retire Basic auth for Client Submission (SMTP AUTH) | Microsoft Community Hub

For any questions or guidance regarding this change, please contact Unit4 Customer Support, referencing this notice in the subject line.