Although you may think there is little place for yet another mail client in today's world, the developer of Revolver Mail has been refining its product for quite some years now.
Revolver Mail is actually not just a mail client - it's three utilities in one, namely an email client, address book and an organizer. The good news is that it works across networks - so you could even use it in your office if you wanted - and even better, it's free.
One of the major selling points of Revolver Mail is it's security features. Revolver Mail boasts an encrypted database that the developer guarantees offers secure automatic server recognition. The general interface, setup procedure and functionality are also excellent. When you start the program, you have a setup wizard which will configure it for Single, Network or Client setups.
The big disadvantage of Revolver Mail is that it only supports POP servers, so those using IMAP won't be able to use it as a mail client. The app doesn't support Exchange protocols either, which will render it useless for most business users. This is a real shame because Revolver Mail shows a lot of promise and seems a robust, lightweight and powerful alternative to Mail or Entourage. The developer site is only in German also, which isn't very helpful when looking for support (unless you speak German, of course).
Revolver Mail is a very impressive package but the lack of IMAP or Exchange support will mean it won't be suitable for many.