I have the following setup: I use Ubuntu 12.04 LTS as a main working system (host) and Windows 7 running in VirtualBox as a secondary system (guest). I've created a profile in Mozilla Thunderbird (v.24) located in the folder accessible by both systems. Since VirtualBox uses the same user ID in the host system, there are no issues related to sharing the same folder between multiple users.
1) I used Thunderbird running on guest OS (Windows) to create the profile and to setup the mail account inside the profile.
2) Then I created a new Thunderbird profile in Linux and linked it (through profiles.ini) to the folder with profile created at step 1.
3) I made corrections to the file prefs.js according to instructions here: http://web.archive.org/web/20050207141558/http://texturizer.net/thunderbird/share_mail.html (Replaced Windows-specific absolute path syntax with Linux-specific absolute path syntax, removed lines containing "[ProfD]").
I used the following sources of information:
2) the link mentioned previously;
I tested this setup under Windows and Linux (I haven't tested them yet working simultaneously). Everything seems to work fine (currently I am keeping all my mail on the IMAP server, therefore all my inbox messages are not downloaded to the profile/account folder).
1) My sources of information seem to be rather outdated (see above). I am not sure whether editing prefs.js file was required.
2) It would be fine if someone who is engaged in development of Thunderbird could answer my question and tell the world what is the right procedure to organize the profile sharing between several instances of Thunderbird running on Windows and Linux (possibly, running simultaneously).
3) What if the mail is downloaded from the IMAP server and stored in the profile folder?
4) What if some instances of Thunderbird use extensions (Lightning) but the other don't?
5) What if some instances of Thunderbird are running under different user IDs (i.e. the profile folder is shared between several users on Linux systems)? What steps in terms of chmod / chown / chgrp are required in this case?
In my opinion all these questions need to be answered if we are going to use Ubuntu Touch with Thunderbird on a mobile device accessing Thunderbird profile stored in the cloud (Ubuntu One?)/ NAS server. (Please correct me if I am wrong)