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In September 2021, we announced that effective October 1, 2022, we will begin disabling Basic authentication for Outlook, EWS, RPS, POP, IMAP, and EAS protocols in Exchange Online. SMTP Auth will also be disabled if it is not being used. See full announcement: Basic Authentication and Exchange Online – September 2021 Update.
– https://docs.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/deprecation-of-basic-authentication-exchange-online#when-will-this-change-take-place
“Basic Auth" or “basic authentication” means authentication with only a user name and password. See What is SMTP AUTH? below.
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Microsoft publications and announcements avoid giving a clear, explicit definition of SMTP AUTH. They do define what Basic Authentication means and then use SMTP AUTH in the same sentence.
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Microsoft does not clearly define what SMTP AUTH means. |
Basic Authentication simply means the application sends a username and password with every request (often stored or saved on the device).
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Please note this change does not affect SMTP AUTH – we will continue supporting Basic Authentication for the time being. There is a huge number of devices and appliances that use SMTP for sending mail, and so we’re not including SMTP in this change– https://techcommunity.microsoft.com/t5/exchange-team-blog/improving-security-together/ba-p/805892
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