Investigate support for OAUTH authentication with Office 365

[nblumhardt]

While SMTP with basic authentication remains supported on Office 365, Microsoft is pushing towards OAUTH token-based authentication for most purposes:

https://techcommunity.microsoft.com/t5/exchange-team-blog/basic-authentication-deprecation-in-exchange-online-may-2022/ba-p/3301866

This plugin may add support for this too, but more investigation is needed: it currently looks as though the differences in configuration and functionality would be significant enough to warrant development of a new/forked HTML email app for this purpose.

See also:

• jstedfast/MailKit#989
• https://docs.microsoft.com/en-us/exchange/client-developer/legacy-protocols/how-to-authenticate-an-imap-pop-smtp-application-by-using-oauth

[harris2310]

Hello there, I could resolve this issue for you