The mail must flow!

You need to configure your firewall to allow mail traffic between your mail server and the Internet. Which of these ports would be the most appropriate to open in your firewall?

A) tcp/80

B) tcp/22

C) tcp/25

D) tcp/110

E) It’s all random, just pick a number

The answer: C) tcp/25

TCP port 25 is commonly used by SMTP to transfer email between mail servers.

Want to know more? Watch “Common Ports.”

The fundamental languages used over our computer networks are a standard set of protocols that are used around the world. In this video, you’ll learn about protocols and the set of standards associated with TCP/IP. You’ll also learn the essentials of TCP/IP and how subnetting can be used to build today’s modern networks.