"User is authenticated but not connected" problem with thunderbird

Question

"User is authenticated but not connected" problem with thunderbird

JMR 0

Hello,

When I try to read/write mails from my personnal Outlook account on my laptop and my android phone, I use MS Authenticator to configure and approve connexion but I always have the message "User is authenticated but not connected". In fact, I can't use my mail account. The only way is to use Outlook online.

I can't find any solution on the web.

Thank's for youy help

0 comments

1 answer

Your answer

Answer 1

Hi JMR,

Since Outlook on the web works correctly, your Microsoft account appears to be functioning normally. The problem is more likely related to the way Thunderbird (or the Android mail client) is configured to connect to Outlook.com.

Please make sure the account is configured to use OAuth2 authentication for both IMAP and SMTP. Older authentication methods may no longer work consistently with Outlook.com.

You can follow Mozilla's official guide for configuring Microsoft account authentication in Thunderbird:

Microsoft OAuth Authentication and Thunderbird in 2026 | Thunderbird Help

If Thunderbird was previously configured using different settings, I also recommend:

Removing any saved Microsoft/Outlook credentials from Thunderbird.
Removing and re-adding the account.
Completing the Microsoft sign-in flow again when prompted.
Verifying that both incoming and outgoing servers use OAuth2.

If the issue continues after following the guide, please provide:

Your Thunderbird version
The Android mail application name/version
Whether the account is Outlook.com, Hotmail.com, Live.com, or a Microsoft 365 account
A screenshot or the full text of the error message

That information will help identify whether the issue is related to Thunderbird's OAuth configuration, cached credentials, or the mail client itself.