CompTIA Network+ (N10-007) — Question 3

A junior network technician is setting up a new email server on the company network. Which of the following default ports should the technician ensure is open on the firewall so the new email server can relay email?

Answer options

• A. 23
• B. 25
• C. 110
• D. 143

Correct answer: B

Explanation

Port 25 is the standard port used for SMTP (Simple Mail Transfer Protocol), which is required for sending emails. Options A (23), C (110), and D (143) are used for other protocols; port 23 is for Telnet, port 110 is for POP3, and port 143 is for IMAP, none of which are used for relaying email.