Using classic Outlook for Windows in business environments
You've got to use the IMAP for incoming and SMTP for outgoing server setups!
However, in my WIN11 environment I had to delete, then re-create the e-mail accounts in order for the operation to work properly.
| IMAP server | outlook.office365.com |
|---|---|
| IMAP port | 993 |
| IMAP encryption | SSL/TLS |
| Authentication Method | OAuth2/Modern Auth |
| SMTP server name | smtp-mail.outlook.com |
| SMTP port | 587 |
| SMTP encryption | STARTTLS |
| Authentication Method | OAuth2/Modern Auth |