Microsoft has started to disable Basic Authentication (affecting Teams and Exchange Online)

 Microsoft is serious about removing the Basic Authentication protocols from their services. The change was announced back in 2019, but has been delayed a couple of times. Earlier this fall Microsoft announced there would be on further delays, and that preparations for the change should be made.

Earlier this week I was notified about the coming change to my tenant through the Admin Message Center. 14 days from now, basic authentication will no longer be available to me: 

"14 days from today we're going to turn off Basic Authentication for POP3, IMAP4, Remote PowerShell, Exchange Web Services, Offline Address Book, MAPI, RPC and Exchange ActiveSync protocol in your tenant, and will also disable SMTP AUTH completely. Note: Based on our telemetry, no users in your tenant are currently using Basic Authentication with those protocols and so we expect there to be no impact to you."

This coming change can have a major impact on many organizations. As a consultant I am engaged in multiple companies facing the challenge of preparing for this change. It might seem trivial, but most organization have over time implemented many services that are using basic authentication without being aware of them. The best way of preparing for this is by starting to go through your sign-in logs in Azure AD and identify any user who use basic Authentication. Some of the things I have noticed are using basic authentication are: Many services reading calendar information (like switchboard integrations), printer services, old mobile devices (often up to date, but wrong configuration), Microsoft Teams Rooms not set up for modern authentication, 3rd party and self developed applications.

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