After going through a total of four Beta versions (Thunderbird 3 Beta 4 was released back in September) Mozilla’s email client has finally reached the Release Candidate (RC) milestone in its development process. Windows, Mac OS X and Linux users alike can now download Thunderbird 3 RC1 and enjoy the software’s enhancements and new features.

“The Thunderbird 3.0 Release Candidate is now available for download. This milestone is focused on providing a preview of the functionality provided by the new features and changes that will be included in Thunderbird 3.0. Please note: the Thunderbird 3.0 Release Candidate is a public preview release intended for developer testing and community feedback. It includes many new features as well as improvements to performance, web compatibility, and speed. We recommend that you read the release notes and known issues before installing this release candidate,” announced Mozilla.

Here is what you can expect to get from Thunderbird 3 RC1:

• New Search with Advanced Filtering Tools
• New Global Search Field with Autocomplete
• New Mail Account Setup Wizard
• Redesigned Mail Toolbar
• Tabbed Email Messages
• Smart Folders
• New Message Summary View
• Column Headings
• Message Archive
• Activity Manager
• New Add-ons Manager
• Improved Address Book
• Improved Gmail Integration
• Integrated with Vista search results (Windows version only)
• Integrated with Spotlight (Mac OS X version only)
• Thunderbird 3 can import from Mail.app, can read your OS X address book, and can use Growl for new mail alerts (Mac OS X version only)
• IMAP Folder Synchronization

Mozilla would like those of you that download and test Thunderbird 3 RC 1 to provide feedback on the following items: the new search tools, tabbed email, message archiving, new mail account setup wizard.

If you would like to get Thunderbird 3 RC1, a download location is available here.
We suggest you take the time to read the Thunderbird 3 RC1 release notes as they present the software’s new features in greater detail.