How to troubleshoot autodiscover functionality in a Plesk server?

Question

How to troubleshoot autodiscover functionality in a Plesk server?

Answer

1. Verify the server configuration for mail clients

   1. Connect to the server via SSH

   2. Run the following command, replacing example.com with the domain name to test and [email protected] with an existing mailbox name:

      # curl https://example.com/mail/[email protected]

      If content section is not empty and contains hostnames and ports, it means that the server generates autodiscover configuration correctly.

2. Verify SSL certificates of ports 465 and 993 by following How to verify that SSL for IMAP/POP3/SMTP works and a proper SSL certificate is in use

   1. Test SMTPs specifying your website name and SMTPs port:

      example.com:465

   2. Test IMAPs using website name and IMAPs port:

      example.com:993

      If a certificate is not valid, follow the steps from article How to assign an SSL certificate per domain to secure the mail server in Plesk (SNI support)?