is it somehow possible to tell CiviCRM to use a different IMAPS port rather than 993/tcp?
Kind regards, Walter
You would have to hack this line and change the second parameter from null to your port: https://github.com/civicrm/civicrm-core/blob/92584a7a5e7181a35482f2e7485816b91411a84b/CRM/Mailing/MailStore/Imap.php#L74