What to keep/copy from a Thunderbird profile?

Question

During my last years of using Mozilla Thunderbird for my E-Mailing, I always copied my whole profile folder to a new computer or a reinstalled system, which worked fairly well. I use the Lightning AddOn for calendaring and sometimes also Enigmail for secure messaging.

For a few months now, Lightning is behaving strangely. Oftentimes when I start Thunderbird, the Today pane misses all buttons and events and in the calendar view, the events are displayed but grayed out and no synchronization is possible. My assumption is that the contents of my profile folder over the years accumulated old data that now confuses the current program version(s). I suppose that it would work to create a new profile, but if possible, I would like to avoid the hassles of recreating all accounts and settings and just copy over the data which is really needed and current.

Question: What contents in the Thunderbird profile folder are really needed to describe the installed accounts including its settings? Is there a description of the profile folder structure somewhere around, besides the Thunderbird source code?

Answer 1

Ok, I guess I figured it out. Some help can be found on Files and folders in the profile, but I ended up using Meld to do a directory diff between the original profile folder and a newly created one. I then copied the following directories and files:

• prefs.js: Probably the most important file, which contains all settings, most notably all accounts, server settings, even settings of AddOns like the registered calendars in Lightning.

• global-messages-db.sqlite: I copied it because it's fairly large, but according to the page linked above it is just for the global search and will be rebuilt if missing.

• ImapMail/: This contains the downloaded messages, but could perhaps be skipped as well, resulting in all messages (in all folders, also Sent!) being redownloaded.

To also copy over the stored passwords, I duplicated logins.json, key4.db and cert9.db.

Not directly related to the new profile, but I first experienced that all of my Local Folders outside of my profile were missing, despite the correct absolute path being set in the account settings. A check of the Config Editor with search for "Local Folders" revealed two directory paths, though. One is the absolute path from the account settings, but then there is mail.server.server1.directory-rel, which stores the same path, but relative to the profile folder. Since I created the new profile in a different location, this matched no longer. So I updated the value and now the folders are back and so far, everything seems to run fine again. Should anyone ever see the Local Folders gone, this might be the cause. I found the hint on the Local Folders page of MozillaZine.

Bye, Philipp