A. SMTP
B. POP3/IMAP
C. HTTP
D. FTP

Explanation:

POP3 and IMAP are protocols used to receive emails from a mail server.

POP3 (Post Office Protocol Version 3) downloads emails to your device. Once downloaded, the emails may be removed from the server.

IMAP (Internet Message Access Protocol) keeps emails on the server and synchronizes them across multiple devices.

Example:

If you read an email on your phone and then open your laptop, IMAP allows you to see the same email status on both devices.

Key Points:

• POP3 downloads emails
• IMAP synchronizes emails
• IMAP is more popular today