As mentioned in the introduction, POP3 is typically used when e-mail is to be stored on a client computer. It is most often used when there is an intermittent connection to the e-mail server, for example, while using a dial-up line to access an e-mail account at an ISP. This approach has the advantage that the e-mail is always available to the client, who can work when not connected to the e-mail server. E-mails can be read, and replies created for, when the user is next on line.
The main disadvantage of using POP3 is that e-mail is generally only available on the client PC. If the client PC fails, or is stolen, the e-mail is lost, unless a backup has been made.
POP3 clients can be configured to keep e-mail on the POP3 server for other ...