All Common Mail Ports and Their Purpose
Email protocols and ports (25, 109, 110, 143, 465, 995, 993, 994)A) Non-encrypted portsPort 25 (SMTP): Port 25 is open for Simple Mail Transfer Protocol (SMTP) services and is used to receive e-mail. Many mailbox providers abbreviate it as pop without adding 3 (such as pop.gmail.com).Port 109 (POP2) – Obsolete: Port 109 is open for POP2 (Post Office Protocol Version 2) services and is intended to receive mail. When you send an email to someone, a dynamic port on your computer (greater than 1024) connects to port 25 on the mail server, and the email you send is transferred to the mail server and stored there.