hi,
I've made some changes to ThunderbirdPortable.nsi to get TB-Tray(http://sniperbeamer.de/tbtray) to work.
Complete package containing TB-Tray, modified source and compiled exe is available at [link removed by moderator JTH. Use of the Mozilla trademarks by PortableApps.com is under a license agreement that does not extend to 3rd parties. While you're free to modify the launcher under the GPL, you can't use the Thunderbird name or logo in connection with it, sorry.]
bugfix
Welcome to PortableApps.com, bugfix.
While we appreciate the effort, you can't use the Mozilla trademarks (like the Thunderbird name and logo) without their specific permission. We have a license agreement but it doesn't extend to 3rd parties. Unfortunately, this means you can't distribute a compiled version, sorry.
As an aside, the Minimize to Tray extension does work with Thunderbird Portable, but it needs to be hacked to work with the current Thunderbird releases (max version is set to an old release).
Sometimes, the impossible can become possible, if you're awesome!