At work we have pop access to the state shared email system. Every so often I have to check a users box to see if the box is jammed with a huge message or just to make sure the account is active. The easiest way for me to do this is using telnet. Below are some basic commands to get you going. If you want to know more lookup RFC 1725.
telnet pop3.mailserver.com 110 <– or what ever port your pop server is on
Commands
USER –this one is pretty straight forward. For a valid user you should get “+OK Password required for <account name>.”
PASS — again pretty easy. Reply after authentication should be: “+OK <account name> has <n> message(s) (MMMMM) octets”, where <n> is the number of messages in the mailbox (MMMMM) is the total size of all messages.
LIST — Lists all the messages by number as well as the size
RETR — this command along with the message number will display the message in text format. ex. retr 3
DELE — delete the message. ex. dele 3