How to renew the SSL certificates for dovecot and postfix
Make a backup of the existing SSL key and certificate file cd /etc/pki/dovecot cp -a certs/dovecot.pem certs/dovecot.pem.old cp -a private/dovecot.pem private/dovecot.pem.old Create the new SSL certificate for two years: openssl genrsa -out private/dovecot.pem 1024 openssl req -new -x509 -key private/dovecot.pem -out certs/dovecot.pem -days 730 Restart Dovecot and Postfix sudo systemctl restart dovecot sudo systemctl restart postfix Check the start and end dates for the certificate: openssl x509 -dates -in certs/dovecot.pem