Which three protocols are commonly used for email retrieval and sending?

Which three protocols are commonly used for email retrieval and sending?

• A. DNS, SSH, FTP
• B. POP, IMAP, SMTP
• C. HTTP, HTTPS, SMTP
• D. IMAP, LDAP, SNMP

Answer: (B)

Email relies on dedicated protocols for two jobs: retrieving messages from a mail server and delivering messages to other servers. For retrieval, you use POP or IMAP. POP is simpler and often downloads mail to the client (and may remove it from the server), while IMAP keeps mail on the server and synchronizes the state across devices. For sending, SMTP handles the submission of outgoing messages from a client to a mail server and the transfer between mail servers to reach the recipient. The other options don’t fit because they serve different purposes. DNS translates domain names to IP addresses; SSH provides secure remote command access; FTP handles file transfers. HTTP/HTTPS are for web traffic; LDAP is a directory service protocol; SNMP is for network management. None of these are the standard trio used for email retrieval and sending.

Email relies on dedicated protocols for two jobs: retrieving messages from a mail server and delivering messages to other servers. For retrieval, you use POP or IMAP. POP is simpler and often downloads mail to the client (and may remove it from the server), while IMAP keeps mail on the server and synchronizes the state across devices. For sending, SMTP handles the submission of outgoing messages from a client to a mail server and the transfer between mail servers to reach the recipient.

The other options don’t fit because they serve different purposes. DNS translates domain names to IP addresses; SSH provides secure remote command access; FTP handles file transfers. HTTP/HTTPS are for web traffic; LDAP is a directory service protocol; SNMP is for network management. None of these are the standard trio used for email retrieval and sending.