Outlook IMAP not working, User is authenticated but not connected

Question

Using Thunderbird with Oauth2 method and disabled ipv6, still can't read emails from IMAP server outlook.office365.com port 993 via SSL/TLS

The current command did not succeed. The mail server for account xxx@yyy.com responded: User is authenticated but not connected.

Server outlook.office365.com has disconnected. The server may have gone down or there may be a network problem.

Answer 1

Hi @Dennis-6654 ,

According to the official document, Starting in February 2023, we will reject a small percentage of connections that use TLS1.0 for POP3/IMAP4. Clients should retry as they do with any other temporary error that can occur when connecting. Over time we will increase the percentage of rejected connections, causing delays in connecting that should be more and more noticeable. The error will be:

TLS 1.0 and 1.1 are not supported. Please upgrade/update your client to support TLS 1.2. Visit https://aka.ms/popimap_tls.

We intend to fully disable TLS 1.0 and TLS 1.1 for POP3/IMAP4 on the regular endpoint by the end of April 2023.  Affected customers will receive a Message Center post in a few days notifying them of this change.

Additional documentation can be found here: Opt in to the Exchange Online endpoint for legacy TLS clients using POP3 or IMAP4.

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