What Is a POP3 Mail Server?

POP3 mail servers allow users to download emails for offline reading.

POP3 mail servers store and send emails to users on command. POP3 is a mail protocol available for corporate and personal email, as well as web-based email programs, such as Gmail and Yahoo! Mail.

Function

A POP3 mail server stores email. To access email stored on the server, the user must log into a POP3 mail client, which then communicates with the POP3 mail server. Emails are downloaded on demand; the user's inbox cannot update in real-time without sending a new request to the POP3 mail server.

Advantages

POP3 mail allows users to store and read emails offline. It is ideal for nonshared inboxes and users with sporadic Internet access.

Disadvantages

By default, POP3 mail servers do not store messages once they have been downloaded. While this is a security feature, it can also lead to data loss if the downloaded message is accidentally deleted.

Alternatives

IMAP4 is the alternative to POP3. IMAP4 mail servers store mail on the server and send copies to the user when requested. Most email clients support both POP3 and IMAP4 mail servers.

References

• PC Magazine: POP3 Definition
• Microsoft: How POP3 Service Works
• Microsoft: Understanding POP3 and IMAP4
• Event Helix: POP3 Tutorial Sequence Diagram