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POP3 or Post Office Protocol version 3 is a one-way incoming mail protocol that downloads a copy of an email message from the email server to a local machine. Once the post office protocol completes the process, it deletes the original data from the server’s mailbox.

How is POP3 Used?

In simple terms, when a mail message is sent to a recipient it is received by the recipients email server. If a user’s mail client is set up with the POP3 protocol, the user can download all copies of messages to his mail client. Once the message is downloaded locally, the email server then deletes the original message from the email server.

Before the download of the message to the user’s local machine, the mail server will perform a DNS lookup to determine whether the mail is from a known spam server.

What is the difference between IMAP and POP3?

The main difference between IMAP and POP3 is the way in which the messages are stored. IMAP does not store the messages locally, and the user only sees a list of the messages on the server. With it, messages are only downloaded when a user opens the message on their mail client.

In contrast, POP3 download the messages to the user’s device locally, whether it is a PC, phone, or tablet. With IMAP, on the other hand, the storage of the mail server can become full. This is one benefit of POP3 because the possibility that the user’s mail server’s storage will be exceeded it minimized. This, ultimately, improves deliverability because the mailbox won’t reject mail because it is full.

POP3 also works better if the user has a poor internet connection and needs the mail to be available offline, or when the user downloads a large number of emails and only uses one device to access the emails.

IMAP is better when the user wants to access their email from anywhere and on any device like a work computer, a home laptop, or a smartphone, where they need to be able to manage their mailboxes remotely, or where they have limited storage space. It does, however, require a constant Internet connection.

Despite some of the benefits that POP3 offer, IMAP is the better option for most people simply because the number of devices that people use these days and the availability of Internet services almost anywhere.

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