Thunderbird  9.0 Beta 3
Mozilla Thunderbird makes e-mailing safer, faster, and easier with features such as intelligent spam filters, a built-in RSS reader, and quick search. Thunderbird was designed to prevent viruses and to stop junk mail.
Thunderbird includes tabbed e-mail, new search tools and indexing, smart folders, support for Firefox, a simplified setup wizard and robust junk protections that include phishing and spam filters.
Key Features Include:
- Tabbed email.
- An Archive feature similar to the one found in GMail.
- Lightning fast search.
- Smart folders.
Thunderbird has junk mail tools that have been updated to stay ahead of spam and features anti-phishing protection.