Moving the entire Thunderbird folder, as the support article describes, works best if the version of TB on both computers is exactly the same. Otherwise, the easiest way is to copy the contents of the W7 profile folder into the profile folder that is created on Linux after first run. Delete the contents (not the folder) of the Linux profile folder before copying in the contents (not the folder) of the W7 profile. One more thing: delete the pkcs11.txt file in the profile to avoid passwords not being read from the stored passwords file.

As for the address books, what is the TB version on W7, and what is the version on Linux?

Ah ha - the windoze version is 78.6.0 while the Linux version is 68.10.0. I tried uninstalling and reinstalling Tbird a couple of times by various means but I always get 68.10 back again. Is there anyway to make this work and not loose years worth of email or am I stuck with Windows 7 until the Linux packages finally catch up?

Update - I think I've got it mostly working. I did a clean install of Tbird and then followed the directions given above about copying the contents of the profile folders. I did not realize initially that those oddly named folders were the profile folders. Tbird gave an error on start up about a newer version, so I created new profiles for each email account and it seems to be working. While I had windoze fired up I exported the address books and imported them into the Linux version. It would appear that all organization has been lost but at least the addresses are still there. All of my filters are gone so I will be a while recreating those.  :(

But, given major change in OS and reversion of Tbird viersion, it's working, and that's a win.  :)

If I may be allowed to editorialize a bit: the above referenced support article is unclear and incomplete. The process to copy contents of folders needs to be clarified and an explanation of how to identify your profile folder(s) added, version issues need to be discussed, there needs to be mention of the pkcs11.txt issue and that things like address books and filters are not covered by this procedure.

Stepping on to a taller soapbox, this whole process is an awful way of doing things. Tbird needs some mechanism to transplant all of the users "stuff", and by that I mean mail, address books, filters, server settings, and anything else from one place to another in one operation regardless of OS or version.

Thank you.

Filters can be copied between profiles, and accounts, by copying the msgFilterRules.dat files that are stored in each account subfolder of Mail and ImapMail, which are subfolders of the profile folder, e.g. look in Mail/pop.gmail.com for the dat files.

If the entire profile is copied between setups, the address books and filters are included. But when changing from one major version to another, such as 68 to 78, the best results are achieved by creating a new profile and transferring data manually in separate parts.