A user can send email but cannot receive email. Which protocol should be checked?

A.
SMTP

B.
DNS

C.
FTP

D.
POP3

Explanation:
SMTP is used to send email while POP3 is used to receive email.
Incorrect Answers:
A: SMTP is used to send email while POP3 is used to receive email.
B: DNS is used for host name to IP address resolution. It is not used for transferring files. C:
The File Transfer Protocol (FTP) is used to upload and download files on the Internet using an FTPO client and server.
References:
David Groth and Dan Newland, A+ Complete Study Guide (2nd Edition), Sybex, Alameda, CA, 2001, pp. 746.