It has almost been too long since Mozilla provided an upgrade for its email client Thunderbird. In late 2009, Thunderbird 3 finally arrived and brought massive improvements.

A major new feature in Thunderbird 3 is tabbed email browsing. The idea is to view separate inboxes or emails in parallel tabs. However, more and more extensions emerge, which exploit the tab feature to add web browser capabilities to Thunderbird.

Most of these extensions are experimental, meaning they are very new and haven't passed the public review process yet. All extensions covered in this article were thoroughly tested and didn't cause issues, neither alone nor in combination with other standard extensions for Thunderbird 3.

ThunderWave (experimental)

Toolbar buttons are a convenient way to launch applications into Thunderbird tabs. So they essentially work like a bookmark. Since Google Wave basically tries to become "email reloaded", it's a good idea to integrate it into Thunderbird, i.e. "old school" email.

Is Google Wave still all Spanish to you? Maybe this video explaining Google Wave "Pulp Fiction" style can fill you in.

If you're going to add multiple such buttons, you will soon run out of space in your email toolbar. Thus I recommend to create a new custom toolbar just for your new extra buttons. Right-click on any existing toolbar and select > Customize and a > Customize Toolbar window will pop up. At its bottom, click the > Add New Toolbar button, enter a name, and hit > OK. Now you can drag and drop buttons from the > Customize Toolbar window onto your toolbar.

Google Calendar Tab (experimental)

In Thunderbird 3, you can still use Lightning and Provider for Google Calendar. Now you can also use this add-on to launch Google Calendar within a Thunderbird tab. Sadly, there is no toolbar button provided, just an option within the > Tools menu.

Within the add-ons options menu you can switch from > Google Calendar to > Google Apps for your domain.

Addressbook Tab (experimental)

You already saw the toolbar button for this add-on in the first screenshot. With AddressbookTab you can open the address book within a tab, rather than in its separate little window.

ThunderTabs (experimental)

Here is the one extension with which you can open any website, given you know the URL by heart. Simply click ThunderTabs' toolbar button, a little JavaScript window will load, enter your URL, and hit > OK.

ThunderBrowse

ThunderBrowse, finally, goes all the way and represents the most comprehensive extension in this series. If you really want to browse with Thunderbird, you have to get this extension. Besides, it's no longer experimental and has been receiving great reviews.

First of all, it comes with a ton of options. You can define how links embedded in emails open, how tabs are handled, you can create Hotkeys for opening the ThunderBrowse window or a ThunderBrowse tab, and much more.

To access all these options, go to > Tools > Add-ons > Extensions > ThunderBrowse and click > Options.

Let me give you a quick overview of some of the main features.

You can quickly open a new ThunderBrowse tab using the icon at the top right of your tabs.

Depending on which options you selected, it will open a Thunderbird tab or a tab within the message window. No matter which of your accounts or folders you open, the tabs you see in the message window of one will be the same in any other.

It may look cluttered at first, but it's incredibly useful. Imagine someone sends you a reference and you want to quickly review it before reading the rest of the email. Previously, you would have to load it in your browser and switch back and forth between two applications. Now you can open the link in a Thunderbird tab or in a ThunderBrowse tab right next to the email you're reading.

Of course, you can also open links as you please using the right-click menu. Besides opening in a tab or in your browser, you can also open the link in a new (separate ThunderBrowse) window.

With these tab options available in Thunderbird 3, who needs a browser?

So tell me, what can your browser do that Thunderbird presently can't?