Certified Ethical Hacker (CEH v12) — Question 315

Which of the following commands checks for valid users on an SMTP server?

Answer options

• A. RCPT
• B. CHK
• C. VRFY
• D. EXPN

Correct answer: C

Explanation

The correct answer is C, VRFY, which is specifically designed to verify if a user's email address is valid on the SMTP server. Option A, RCPT, is used to specify the recipient of an email message but does not check validity. Option B, CHK, is not a valid SMTP command, and Option D, EXPN, expands a mailing list but does not confirm individual user validity.