Please follow these instructions to install your SSL certificate on Cyrus IMAP Server:
1. Once you received your SSL certificate by e-mail, please copy and paste it into a text file and save the file with the .crt extension. (Include the tags -----BEGIN CERTIFICATE----- and -----END CERTIFICATE-----).
2. /ROOTS|Get your intermediate certificate. Copy and paste the contents into a .crt file by using a text editor.
3. You have to concatenate your Domain Certificate, the intermediate certificate and your private key into a single server.pem file:
-----BEGIN CERTIFICATE-----
(your_domain_name.crt)
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
(your_intermediate.crt)
-----END CERTIFICATE KEY-----
-----BEGIN RSA PRIVATE KEY-----
(your_domain_name.key)
-----END RSA PRIVATE KEY-----
4. Open the Cyrus IMAP configuration file imapd.conf (usually located in /etc/imapd.conf).
5. Modify or add the following lines (make sure the files are readable with chown cyrus command)
tls_cert_file: /path-to-file/server.pem
tls_key_file: /path-to-file/server.pem
tls_ca_file: /path-to-file/server.pem
tls_ca_path: /path-to-ca-map/
6. Restart Cyrus.