Post Office Protocol, the method by which most people download their email. See also IMAP, SMTP.

Here is a quick and dirty guide to directy accessing your POP3 server.

1. Go to any telnet program.
2. Connect to your mail server, on port 110.
3. You should see a welcome message.
4. Type "user xyz" (xyz = username, no quotes, you may need to turn on local echo to see what you are typing.)
5. It should respond "+OK". Type "pass foobar" (foobar = password).
6. Again it should say "+OK". In fact from now on assume it should always say "+OK". If you type something wrong, it will say "-ERR".
7. Type "list" to see a list of the message numbers and their sizes.
8. Type "retr x" (x = message number) to read a message. *
9. Type "dele x" to mark a message for deletion when you quit.
10. Type "rset" to unmark all messages so they will not be deleted.
11. Type "quit" to quit and delete all marked messages.

* If it is a long message it may scroll off the screen. You could turn on logging and look at it later.

This is not the whole POP3 protocol, just what you will probably use.

What is this good for? You can quickly read your mail from just about any computer on the internet. And if your mail program breaks, you can use this as a emergency backup. You can also impress people.
In addition to infinity's excellent instructions above, there are two more commands you might want to know about:

12. Type "stat" to get a simple message of how many messages you have.
13. Type "top x y" to get back the first y lines of message x. This is unbelievably useful in that you can say something like "top 1 0", and get the first zero lines of message 1-- in other words, only the headers. This is how you see who the message is from without reading it. After using top x 0 you are then free to decide whether to dele the message or retr it.

Once you get used to this, you begin to like it a lot-- checking your email from anywhere without having to find and set up a mail program gets really nice. If you want to see the full guide to the protocol by hand, it's all described nicely in the RFC..

Log in or register to write something here or to contact authors.