What could be the problem (dovecot + IMAP)?

Question

Mail server

Good day!
There is an ISPManager control panel with configured DOVECOT mail servers.
I connect via IMAP via Mozilla Thunderbird - everything is ok!
Connecting via IMAP via Outlook: Error "Logging in to the incoming mail server (imap error) The server refused to log in. Please check that the username and password are correct."
Connecting via IMAP via TheBat!:
IMAP - Connected to the IMAP server (mail.siteru)
IMAP - Dovecot ready.
IMAP - Authentication (user: "user", method: "LOGIN")...
IMAP - Authentication failed.
At the same time, POP3 connections work fine for both Outlook and TheBat!
What could be the problem?

Answer 1

Linux does not support the digest-md5 authorization that Outlook uses. Disabled this type in dovecot settings.