I have the fabulous MS Outlook.. which updates every minute, and has a little box that pops up in the lower right hand corner when I have mail.
It's wonderful, since I can create folders and rules for incoming messages (dividing things into specific folders for specific people/studios/co-workers).

Generally, I keep it open to the "Unread Mail", since anything new gets sent there too, no matter what folder it's delegated to, and it stays there until I change folders. I also have the folder that has all the "marked for follow up" mails in there, so if I ever have things piling up, I just mark them, and I can get back to them when I get done with whatever I'm doing.

Since a lot of my time is spent trading mails back and forth, and on the phone with carious affiliates and studios, I can occasionally have about...er...20 emails open at a time that I'm working on...

So the answer is... I don't stop checking. :crazyeyes: