Point of Presence?

[xyzzyplugh]

Where and what is 'POP3' exactly? Who owns it? How big is it.? If I give your Mum the wool, can she knit me one?

[mopoke]

POP3 is a messaging protocol. It stands for Post Office Protocol (v3). The idea is that a server acts as a repository for your email and holds it until you come and pick it up. So if I send an email to you, then your ISP's mail server will receive it and then store it for you. When you come and pick it up, you use POP3 to retrieve it from their server. So POP3 is a protocol - many people have different POP3 servers which keep mail for themselves or for their clients.