I love Thunderbird. It is both flexible, powerful and user-friendly. But, on Mac OS X, it has the nasty habit of saving a copy of all the opened attachments on the desktop leaving a messy trail… Can something be done about that ? You bet !
I said Thunderbird was flexible, didn’t I ? It is so flexible that it will let you edit tons of hidden parameters if you so wish. Those parameters can be found in the “Thunderbird” menu under the “Preferences” item. In the preferences window go to “Advanced”, then “General” and then “Configuration editor”. Be sure to read the warning that will appear and don’t do anything stupid…
Now for the grand finale, in the about:config window that appeared, control-click (or right-click) anywhere and select “New” and “Boolean value” from the contextual menu that appeared. Then, paste in the following key name browser.helperApps.deleteTempFileOnExitand select true when prompted. Voilà! Now, all those temporary files will be cleaned up when you exit Thunderbird.
This has been tested to work in Thunderbird 3 (but I believe it also works in Thunderbird 2).