I have moved the Thunderbird profile between Linuxes (admittedly all Debian-based) and also between Linux and Windows. (In the latter case, you have to re-install or replace some add-ons which may not work on the new platform.)

But I don't anticipate any difficulty between the two Linuxes you mention. I'd just install Thunderbird on the new one and let it tell you where it looks for its profile, so you know where to paste your original profile. I'd bet a few drinks on it being under ~/.thunderbird in both cases. The location of the Thunderbird executable might be different, but that's not too important, so long as it's in your path, or linked to explicitly in its launcher.

Thanks Zenos for your reply. Can you list down steps to transfer Thunderbird from Fedora 20 to Ubuntu 16? Which files/folders are needed to backup etc.

The key word here is "profile" - that's where all your settings and messages are stored.

This article gives some guidance on working with the profile:

https://support.mozilla.org/en-US/kb/profiles-where-thunderbird-stores-user-data

So:

• find your profile on the first OS;
• copy it to somewhere safe (external drive, USB thumbdrive etc);
• install Thunderbird on your second OS (it may well come as the default email app);
• locate the new (empty) profile created by the new Thunderbird, and overwrite this with the copy you made earlier.

Fundamentally, this means copy ~/.thunderbird from the old OS to the new OS.

Thunderbird itself can help you find the profile. Help|Troubleshooting Information has a button that opens the profile location in your file manager. That's Caja in my flavour of Linux; it may be Thunar or Nautilus or something else in yours.

Note: having found your profile, close Thunderbird before doing any copying, moving, back-up etc.

Thanks Zenos for your reply, it is really helpful for me. I understood the process of transferring ThunderBird.