Exchange Online, Microsoft 365 Experts
From Microsoft Corporation
Technical Bulletin MC338517 · Published Mar 3, 2022
Message Summary
We’re making some changes to improve the security of your tenant. We announced in 2019 we would be retiring Basic Authentication for legacy protocols and in early 2021 we announced we would begin to retire Basic Authentication for protocols not being used in tenants.
7 days from today we’re going to turn off Basic Authentication for Outlook for Windows (Exchange Web Services, Offline Address Book, MAPI and RPC) in your tenant. Based on our telemetry, no-one is currently using Basic Authentication with those protocols in your tenant and so we expect there to be no impact to you.
We previously communicated this change via Message Center: MC191153 (Sept. ‘19), MC204828 (Feb. ‘20), MC208814 (April ‘20) and MC23771 (Feb. ‘21) and you can always read the latest information about our plans to turn off Basic Authentication here.
We will send another Message Center post when we make the change. You may receive additional notifications if any other protocols could be affected.
How this will affect your organization:
Once this change is made, users in your tenant will be unable to access their Exchange Online mailbox using Basic Authentication and this specific protocol.
If Modern Auth for Outlook for Windows is not already enabled in your tenant, we will also enable it, ensuring you can connect securely using up-to-date versions of Outlook. Please see here for additional information.
What you need to do to prepare:
This is for your awareness only. If you experience any issues, please follow your standard support processes.
