SCP Exam SC0-411 Topic 2 Question 44 Discussion

Your network is a mixed environment of Windows, Linux, UNIX, and Novell computers. The routers are primarily Cisco and the network uses a T-1 to connect to the Internet. You are experimenting with setting up a mail server in a production environment for internal use only. So you configure SMTP on a server. You do not want this mail server to receive any requests from anywhere but the internal network. Therefore you have decided to block incoming SMTP traffic at the Firewall. Which port will you block at the Firewall?