Basic Authentication Deprecation – MS Office 365


During the months of October/November 2022, Microsoft has decided that it will begin to suppress the support for sending emails via SMTP for clients that do not support OAUTH2.

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OK. What about that?

It depends on your options and needs.
If the application for sending emails is fully under your control, you have the option of overwriting it.

If it is not under your control (e.g. for historical reasons), but it is possible to replace it, one of the clients that enables OAuth authentication and support send email from command line is e.g. CMail.

A little more about OAuth.