Configuring an Email Server's SSL Certificate
If you want to use your SSL certificate for mail, configure to the following settings.
ISPmanager
In the ISPmanager control panel, go to «Domains» — «Mail Domains» and click «SSL-certificate» on the toolbar.

Replace the key values with your certificate keys and press «OK».

CentOS
Exim Mail Server
Copy the SSL certificate file and the file with the key in /etc/exim/ssl/ . Enable access privileges for these files:
chmod 444 /etc/exim/ssl/mydomain.com.crt chmod 400 /etc/exim/ssl/mydomain.com.key
Where mydomain.com.crt is the certificate name and mydomain.com.key is the name of the file with the key.
Open the exim.conf file for editing:
vi /etc/exim/exim.conf
Make the following edit:
# TLS/SSL tls_advertise_hosts = * tls_certificate = /etc/exim/ssl/mydomain.com.crt tls_privatekey = /etc/exim/ssl/mydomain.com.key daemon_smtp_ports = 25 : 465 : 587 tls_on_connect_ports = 365
Restart the mail server using the command:
systemctl restart exim
Dovecot Mail Server
Copy the SSL certificate file in /etc/pki/dovecot/certs/ and the file with the key in /etc/pki/dovecot/private/. Enable access privileges for these files:
chmod 600 /etc/pki/dovecot/certs/mydomain.com.crt chmod 600 /etc/pki/dovecot/private/mydomain.com.key
Where mydomain.com.crt is the certificate name and mydomain.com.key is the name of the file with the key.
Open the 10-ssl.conf file for editing:
vi /etc/dovecot/conf.d/10-ssl.conf
Make the following edit:
ssl = yes ssl_cert = </etc/pki/dovecot/certs/mydomain.com.crt ssl_key = </etc/pki/dovecot/private/mydomain.com.key
Restart the mail server using the command:
systemctl restart dovecot
Debian
Exim Mail Server
Copy the SSL certificate file and the file with the key in /etc/exim4/ssl/. Enable access privileges for these files:
chown root:root /etc/exim4/ssl/mydomain.com.crt chmod 644 /etc/exim4/ssl/mydomain.com.crt chown Debian-exim:Debian-exim /etc/exim4/ssl/mydomain.com.key chmow 400 /etc/exim4/ssl/mydomain.com.key
Where mydomain.com.crt is the certificate name and mydomain.com.key is the name of the file with the key.
Open the exim4.conf.template file for editing:
vi /etc/exim4/exim4.conf.template
Make the following edit:
tls_certificate = /etc/exim4/ssl/domain.com.crt tls_privatekey = /etc/exim4/ssl/domain.com.key
Restart the mail server using the command:
systemctl restart exim4
Dovecot Mail Server
Copy the SSL certificate file in /etc/dovecot/ and the file with the key in /etc/dovecot/private/. Enable access privileges for these files:
chown root:dovecot /etc/dovecot/mydomain.com.crt chmod 644 /etc/dovecot/mydomain.com.crt chown root:dovecot /etc/dovecot/private/mydomain.com.key chmod 600 /etc/dovecot/private/mydomain.com.key
Where mydomain.com.crt is the certificate name and mydomain.com.key is the name of the file with the key.
Open the 10-ssl.conf file for editing:
vi /etc/dovecot/conf.d/10-ssl.conf
Make the following edit:
ssl = yes ssl_cert = </etc/dovecot/mydomain.com.crt ssl_key = </etc/dovecot/private/mydomain.com.key
Restart the mail server using the command:
systemctl restart dovecot