I've built a thinapp of Thunderbird, and it works just fine... appart from one little thing. It won't automatically register as a the default mail reader. Doing the same thing with Firefox sets it as the default browser, so either there's an "option" that the capture process fails to find or there's a bug in handling the registry correctly...
For thunderbird I've added
Protocols=mailto;news;nntp;snews;Thunderbird.Url.mailto;Thunderbird.Url.news
And for firefox this reads
Protocols=FirefoxURL;ftp;http;https
Thunderbird is actually not registered with Windows XP (SP3) at all, so I can't choose it manually either... the files are there, the shortcuts are there, but Windows seem oblivious to the fact that there is any other mail reader there than OutlookExpress.
Any fix? (And I'd rather NOT have to run 3rd party tools or do registry hacks as this is supposed to work with the msi/thinapp :/)