The first thing you will need is a regular telnet application. No need for anything fancy. Unix has a native telnet client (simply type telnet hostname/IP to telnet to that hostname or IP into port 23 or telnet hostname/IP port to choose a port other than 23). Windows 95 and above also come with a telnet application (it's in c:\windows\telnet.exe, but you can also press start, run and type telnet to run it, telnet hostname/IP to telnet to that hostname or IP and into port 25 or specify a port other than 23 with telnet hostname/IP port).

Next, you need to find your POP3 mail server. Usually it would be something like mail.your-isp.net. For example: my ISP is netvision.net.il, so my POP3 server is located at mail.netvision.net.il. If you already have an Email client that is configured correctly for your POP3 box, go to your preferences dialog boxes and you should be able to find your incoming mail server address there.

Okay, looks like we're pretty much ready for this. Next thing, we telnet to our POP3 server and into port 110 (the default port for POP3). This is what I get when I telnet into my POP3 page:

+OK POP3 [194.90.1.6] v7.60 server ready

Okay, looks good so far. Now we need to identify ourselves. We need to supply our username and password. Your username would usually be in your Email address. For example: my Email address is barakirs@netvision.net.il, therefore my username is barakirs. So we type:

user barakirs (or whatever username you have)

And the server replies with:

+OK User name accepted, password please

Next thing, we need a password, right? So we do:

pass your-password

And the server replies with:

+OK Mailbox open, x messages (when x is the number of messages you have in your inbox)

Or with:

-ERR Bad login

If we supply the wrong password. Now, we want to see what we have, so we first type list to see the list of Emails we currently have (unless, of course, we have 0 new messages). For each Email, we would get a separate line which will contain a message number (a number that identifies each message) and a number that would indicate the size of each message.

Next thing, we want to read our messages. To do this, we type retr #. Retr stands for retrieve. # should be replaces by the message's number. We would then get a full message header (see Sendmail tutorial) and the body of the message.

After we read the message, we would probably want to delete it. In order to do that, we type dele #. Dele stands for delete. # should be replaced by the message's number.

Once you're finished, type quit to close your session.

Final notes

Yup, that's all! Oh, just one more thing - when you log into your POP3 mailbox, it gets locked up so no one can access it while you're inside. A "lock file" is created when you log in and is deleted when you log out, and whenever someone tries to log in the server allows him access only if the lock file does not exist (which means that there's nobody currently logged in).