Yippie! One of Gmail's recent new features was activated for my account: the possibility to have Gmail pick up the mail of another (POP3) mailbox. This way I can have Gmail pick up the emails that my ISP sends me.
After switching to Gmail I haven't used my old email client anymore so I haven't seen any emails from my ISP. On top of that, their web mail interface is so oldskool that it really hurts.
If you're using Gmail you should check it out.