We are 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. You can always read the latest information about our plans to turn off Basic Authentication here.
Today we turned off Basic Authentication for POP3, IMAP4, Remote PowerShell, Exchange Web Services, Offline Address Book, MAPI, RPC, SMTP AUTH and Exchange ActiveSync protocol 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 have previously communicated this change via Message Center: MC191153 on 9/20/19, MC204828 on 2/26/20, MC208814 on 4/6/2020 and MC23771 on 2/4/2021, and most recently in the Basic Authentication – All Protocols Message Center post sent approximately 30 days ago.
How this will affect your organization
Users in your tenant will be unable to access their Exchange Online mailbox using Basic Authentication and any of those specific protocols.
What you need to do to prepare
This is for your awareness only. You have the ability to re-enable specific protocols for the time being – read more here.
Message ID: MC304510