POP3 means Post Office Protocol version3. It is a protocol that offers a simple way to use mailboxes and download messages to their computers. It allows users to download emails from the mail server to the local server and enable them to read the mail even if they are offline. The client POP3 software is installed on the recipient computer while the server POP3 software is installed on the mail server.
It means if you access your account from multiple locations, that may not be the best option for you. But if you use POP3, the messages are stored on your local computer. That reduces the space that your email account uses on your web server. Also, the attachments are downloaded and deleted at the client server.
How does Pop3 operate?
The server starts POP3 services by listening to TCP port 110. When a user checks for new mails, the client will connect to the Pop3 server. The email client then sends its username and password to the server for authentication. Once connected, the client issue a series of text-based commands to retrieve all the messages. It then stores these downloaded messages on the users’ local system as new emails, deletes the server copies, and disconnects from the server; unlike IMAP protocol.
By default, the server emails are deleted once they are retrieved by the client. So the emails now only remain in the particular system, and it would not be possible to access that mail from an email client on another system. The user can get around this issue by configuring the emails client setting to leave a copy of the email on the server.
Pop3 and email applications
POP3 is built into the most popular email clients, including Microsoft Outlook. The protocol will work provided that the email program is configured to host POP3. Each POP3 mail server has a different address that must be entered into the email program for it to connect with the protocol. User must also enter their username and password to receive emails successfully.
Advantages of pop3
- Emails are downloaded to the server computers; messages can be read when a user is offline.
- Opening attachments is quick and easy as they are already downloaded.
- Less server storage space is required, as all emails are stored in client-server.
- Easy to configure and use.
Disadvantages of pop3
- Email cannot be accessed from other machines.
- Exporting the local mail folder to another email client or physical machine can be difficult.
- Email folders can become corrupted, potentially losing the entire mailbox at once.
- Email attachments maybe contain viruses that may expose to the client system.
Although POP3 has been around for a long time, it remains one of the most viable and popular email protocols because of its simplicity. It allows the user to read the messages offline, and there are no limits on the server storage capacity.