The best way to set up your email (provider limitations permitting) is IMAP, this allows for synchronising between the email accounts and any sub folders, changes on one PC will be replicated to the others.
Try to avoid POP if possible, it's an old and less reliable protocol for mail delivery.
If you cannot have IMAP from your current provider and you still want to have e- mail properly synchronised across your PCs, then condiser getting a hosted exchange account, this will provide business class e-mail that will be able to handle more advcanced features such as secure mail and calander sync, extremely cheap as well, worth considering since if you don't leave copies of your mails on the server, then a crash could potentially leave you without any e-mail history!!
Most of the exchange accounts we have are 25gigs so you almost never have to delete anything... ever!
