Installing SSL/TLS Certificates for the Courier-IMAP Mail Server

To install a custom SSL/TLS certificate for the Courier-IMAP (IMAP/POP3) mail server on a Plesk server:

  1. Log in to a Plesk server through SSH as a root user.
  2. Download one or more SSL/TLS certificate files that you want to install.

    Note: IMAP and POP3 each require separate certificate files, but both files can contain the same certificate.

  3. Make a backup copy of the existing default SSL/TLS certificate for the Courier-IMAP mail server.

    For example for RedHat or Fedora operating systems, you need to back up the following default SSL/TLS certificate files:

    • /usr/share/imapd.pem - the certificate enables secure data transfers through the IMAP protocol.
    • /usr/share/pop3d.pem - the certificate enables secure data transfers through the POP3 protocol.

      Note: For other operating systems, the default certificate file locations may be different.

  4. Open a default certificate file using your favorite text editor and replace the contents of the file, with the content of the SSL/TLS certificate file that you want to install.

    For example, the content to be copied from a custom SSL/TLS certificate and pasted in lieu of a default certificate file body should look like this:

    -----BEGIN CERTIFICATE-----

    MIIB8TCCAZsCBEUpHKkwDQYJKoZIhvcNAQEEBQAwgYExCzAJBgNVBAYTAlJPMQww

    ............

    ............

    eNpAIeF34UctLcHkZJGIK6b9Gktm

    -----END CERTIFICATE-----

    -----BEGIN RSA PRIVATE KEY-----

    MIICXgIBAAKBgQDv6i/mxtS2B2PjShArtOAmdRoEcCWa/LH1GcrbW14zdbmIqrxb

    ..........

    ..........

    faXRHcG37TkvglUZ3wgy6eKuyrDi5gkwV8WAuaoNct5j5w==

    -----END RSA PRIVATE KEY-----

  5. Save and close the file.
  6. To finish the certificate installation, restart Courier-IMAP.