Disabling Dovecot - Deciding when to Block Ports (465, 587, 2095, 2096)
The decision to block ports 465, 587, 2095 and 2096 should be made carefully. This tutorial is only for WHM/CPanel servers. Most server administrators begin considering the decision when there are relentless Brute Force attempts at these open ports.
1) Check if you are using your local server to deliver emails for your clients or your organization by doing an MX Entry Lookup