Merge pull request #12314 from nextcloud/backport/12294/stable28

[stable28] fix(admin_manual): Microsoft Outlook email Basic authentication deprecation

admin_manual/configuration_server/email_configuration.rst

@@ -43,6 +43,7 @@ connect Nextcloud to a remote SMTP server:
 
     * STARTTLS cannot be enforced. It will be used automatically if the mail server supports it. The encryption type should be set to 'None/STARTTLS' in this case. See :ref:`here<TLSPeerVerification>` for an example on how to configure self signed certificates.
     * NTLM authentication for Microsoft Exchange is not supported by the new mailer library. Try using `basic authentication <https://learn.microsoft.com/en-us/exchange/client-developer/exchange-web-services/authentication-and-ews-in-exchange#basic-authentication>`_ instead.
+    * Outlook and Microsoft Exchange have discontinued support for Basic authentication. It is no longer possible to use their services as your default email handler.
 
 * Encryption type: None/STARTTLS or SSL