#3088 ✓closed
Samuel Mehr

OAuth2 for Office 365 not working

Reported by Samuel Mehr | June 19th, 2022 @ 05:27 PM

Hi, I'm trying MailMate to replace Gmail as a mail client after my university has disabled the "Send mail as..." functionality of Gmail with our institutional Office 365 email accounts. A colleague recommended the app.

I'm unable to set up access to my institution's Office 365 account, though. The MailMate documentation says the app supports OAuth2 and will allow me to log in with 2-step verification on the first sync. But OAuth2 does not appear for me in the "IMAP Account Settings" window and MailMate appears to try to log into my O365 account in the old-fashioned way (which is then rejected by O365).

I'm running 1.13.2 (5673) on macOS 10.15.7. What am I doing wrong?

Comments and changes to this ticket

  • benny

    benny June 24th, 2022 @ 02:41 PM

    • State changed from “new” to “closed”

    Sorry about the late response. MailMate is a bit in-between releases at the moment. It's not quite ready for a new major release while the public release has several shortcomings (partly due to updates to macOS and other changes out of my control). One of them being OAuth2 for Office365 which wasn't supported at all by Microsoft at the time of the release of the public release (which only supports OAuth2 for Gmail).

    Therefore, to make MailMate work with Office365, you need a test release: Hold down ⌥ when clicking “Check Now” in the Software Update preferences pane to get the latest test release.

    It should be quite stable and it includes a lot of changes compared to the public release.

    I certainly understand if this is a deal breaker :)

  • Alexander Babaev

    Alexander Babaev June 27th, 2022 @ 03:57 PM


    Just updated to the test release. Still no luck with @live.com account. This started just today, as far as I can tell.


  • benny

    benny July 15th, 2022 @ 07:26 AM

    @Alex: @live.com/@outlook.com/@hotmail.com is not Office365. It used to work in MailMate with OAuth2, but it was based on undocumented support by Microsoft (as far as I can figure out from their myriads of documentation) and I'm not really sure it was supposed to work. Therefore the recommended approach is to use an application specific password (and not use OAuth2).

    Hmm, maybe this is not strictly correct. It seems Microsoft users can migrate these email addresses to Office365, but in that that case you should be connecting to outlook.office365.com and that should work in MailMate (in the beta/test releases). They write about this migration here.

  • Alexander Babaev

    Alexander Babaev July 15th, 2022 @ 02:14 PM

    Not using OAuth2 did the trick. Thanks a lot! MailMate is awesome.

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Mac OS X email client.

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