随着Firefox 5的到来，Mozilla的邮件客户端Thunderbird也跳过4.0直接已经更新到了5.0版本，这是Thunderbird 18个月后第一次更新主流版本，带来了全新Gecko 5引擎，加入扩展管理器，提升了启动性能，加入可记忆标签，兼容Intel Mac系统，但停止了对PowerPC Mac的支持。
下载:Mozilla Thunderbird 5
More responsive and faster to start up and use
Thunderbird is based on the new Mozilla Gecko 5 engine
New Add-ons Manager
Revised account creation wizard to improve email setup
New Troubleshooting Information page
Tabs can now be reordered and dragged to different windows
Attachment sizes now displayed along with attachments
Plugins can now be loaded in RSS feeds by default
There are several theme fixes for Windows Vista and Windows 7
Support for Mac 32/64 bit Universal builds (Thunderbird no longer supports PowerPC on Mac)
Over 390 platform fixes that improve speed, performance, stability and security
