When you think of installing a new email client, there aren’t too many options. If you happen to be both a Windows and Mac user, and want to use the same client across both computers, Thunderbird would be your most obvious choice.

Microsoft Outlook and the Mac-based Entourage are obvious options. However, Entourage isn’t the best commercial e-mail client and, to be fair, it isn’t cheap. You have to purchase Mac Office to install it on your computer and most users prefer the free Apple Mail.

Another choice is Postbox. This is a cross-platform commercial email client, based on the Mozilla platform, but with a whole host of new and powerful features that make it worth considering. If you’re used to a tabbed interface in your web browser, then using Postbox will be a breeze. You can open multiple emails within tabs, rather than separate windows. It separates the components of your email, so you can quickly see the main message, attachments, images, links and contacts associated with the email.

Search for an email within Postbox and you do not have to wait minutes for the result. The search options are presented immediately, much like spotlight in Mac OS X.

Reading emails through Postbox is made easy by the use of threaded discussions, so it will group together emails from various people, around the same topic. You can quickly open the topic and see every response. Ideal for following a conversation.