Help I want to download all mail headers (even those I've already downloaded)

[Kettir]

I haven't been using "delete on server" and I'd like to go back and check all the mail waiting on some POP servers and delete anything that I don't want. So I want to get ALL mail on a POP server, even if I've already accessed it via the built in HTC mail app already. Any suggestions on how to do this would be much appreciated.