The code you have so far bears no relation to your problem. With the Net::POP3 module, you can retrieve the mail from your server. You then need to parse out the attachments.

I recommend you first retrieve the mail into a local file for easier debugging and then write a program to parse attachments from the locally saved mail. MIME::Parser is a convenient module to parse the parts of a mail message, and the Mail and Email namespaces hold other MIME parsing modules.