Downloading specific mails using POP3 protocol.

Hello there,

You probably know that *****mail clients are connecting to mailboxes, and then they are downloading small parts (5-20 MB) of uploaded file. After they end this process, they merge these parts, called "segments". Each segment is in one mail, as an attachment. And now the most important part: segments have their numbers, from 1 to X; such a number is usually placed in mail's subject. The *****mail clients are downloading the segments starting with the first and ending on last one. My question is: how to do that using POP3 protocol? Is it possible?

Thank you in advance for your questions for details :).

POP3 is just a simple telnet-style command exchange protocol, but what you describe sounds like Multipart MIME encoding. The naughty-word filter keyed off of something you posted above so I'm not sure what kind of client you are describing.