N10-005 · Question #645
N10-005 Question #645: Real Exam Question with Answer & Explanation
The correct answer is B: Allow TCP port 25. Email requires two distinct operations: (1) Sending email uses SMTP on TCP port 25 - this must be allowed for outbound mail to leave the organization. (2) Receiving/retrieving email from a POP3 server uses TCP port 110 - this must be allowed so clients can download messages from
Question
Options
- AAllow TCP port 23
- BAllow TCP port 25
- CAllow TCP port 110
- DAllow UDP port 25
- EAllow UDP port 110
Explanation
Email requires two distinct operations: (1) Sending email uses SMTP on TCP port 25 - this must be allowed for outbound mail to leave the organization. (2) Receiving/retrieving email from a POP3 server uses TCP port 110 - this must be allowed so clients can download messages from the mail server. Both protocols use TCP, not UDP. Allowing only one port would break either sending or receiving. Port 23 (Telnet) is unrelated to email.
Community Discussion
No community discussion yet for this question.