? You don't download .txt files through pop3, you download MIME messages with structure delimiting body parts (attachments).

Are you saying that you have a multi-part message, supposedly with a part (attachment) whose content is text/plain, but where the boundary is not coming through correctly, so the part (attachment) is not automatically being distinguished from the preceding part (the "body" of the message)?

Or maybe was the message constructed by the sender, by just appending the text inline, directly to the body, so there really is no "attachment" anymore, and no multipart boundary?