Issue: After completing the steps to install a new SSL certificate on your Cisco IronPort ESA you need to assign the certificate to the various Cisco IronPort functions that require encryption (email communications, TLS, Quarantine and admin web pages).
Activating the new SSL Certificate:
To assign the new certificate for inbound SMTP email communication, open Network > Listeners and select the new certificate
Assign the certificate for use in Outbound TLS based email communications:
Note: Specifying a certificate under destination controls tells the IronPort ESA which cert to use *if* TLS is enabled on outbound communications. In other words, specifying the cert in the drop down will not actually enable TLS on the IronPort. Follow these steps to enable TLS on the IronPort ESA.