POP3 Question : How to download Unread messages

Hello everybody,
I am new to Internet programming. Please help me out with this:
I am using POP3 to download e-mail messages from the mail server. The server contains new as well as old (read, but not deleted) messages. My program is required to download only the new messages and then delete them from the server storage. How can my program differentiate between new and old messages? Please help.

Thanks in advance,
- KA

You can use the command UIDL for this.

Just UIDL reports a list of all emails on the box with their id. each id is given away just one time. That means your program has to remember all id's of previously downloaded emails and don't need to download them again.

You can also use UIDL<sp><number>
Then u would just receive the special ID of this one message.

I hope this helped u.