Also referred to as the "Inbound Mail Server", POP3 is the most common protocol that users utilize in retrieving email from a server. With POP3, you are able to leave or delete email messages from the server after you download them.
Unlike web-based email, you do not need to be online in order to view your old email. Outlook, for example, provides an option that allows leaving a copy of new mail on the server. By enabling this, you can receive new mail from a remote location (e.g. somewhere other than your office) – you will get that same mail again upon returning to the office.
This feature analyzes the IP address of your current session to determine which email is “new” for your current location. Because of that, you could have one main location (your office) and several remote locations for fetching your email (a laptop, a client’s computer). However, you’ll be reading the same email over and over at each location until you receive it at your main location whereupon the mail server permanently removes it.
