Incomplete instructions to move Thunderbird emails to another computer

I am unsure of what you are stating. When moving a profile, that always includes the Local Folders as they are part of the profile.

The Local Folders may be kept elsewhere, if you look at the Account Settings > Local Folders, or right-click on Local Folders and select Settings, you will see an option for Local Directory under Message Storage, this path is where the Local Folders files are found, this is not necessarily under the same path as the Profile(s).

This folder needs to be copied as well as the Profile if it is different.

There is also another path for Message Storage for the POP email server settings, again, this could be different from the path for Profiles.

That is also true for each account. My confusion was in trying to figure out whether you were posting a question. It appears you are not. Thank you.

Same issue, with a question. Old computer died, but still have the C: drive intact. In case it matters, Thunderbird was originally installed in 2014, under Windows 8.1. Yes, I really meant old, though Windows was upgraded to 10.

Installed Thunderbird on new Windows 11 computer. Avoided signing in after install, but Tbird created a default profile anyway, "23clqnak.default-release." Found the same instructions as mentioned above, copied everything under the AppData\Roaming\Thunderbird folder. My original profile looks like "2jvbyj1c.default" and both are present under Profiles. When I started Tbird after copying, regular (server based) email came up and appears to be working as it did on old computer, so presumably old profile is being used. However, Local Folders was present but empty.

I located the original Local Folders on my old C: drive under AppData\Local\Thunderbird, with the same profile name. So far, so good. My question is, should I copy EVERYTHING in the Thunderbird folder from the old drive to the new, letting the same-named folders merge? Or, should I delete what is on the new drive first?

And, particularly for the "startupCache" folder, how much does that matter? Each have a "webext.sc.lz4" file, but they are different, old folder has "startupCache.4.little" but new folder has "startupCache.8.little". Trying not to screw this up with some mix-and-match issue. Thanks!

Well, here's my guess on what happened: when you overlayed the new thunderbird folder with your old thunderbird folder, the new profile (not needed) remained, since a file explorer copy does not touch existing files where there is no replacement. So, that extra profile that isn't used could be deleted. You can easily verify that you're using the right profile by clicking help>troubleshootinginformation, scroll to 'profile folder' and click 'open folder'. you should see that you are in the desired old profile. So, you remove the unneeded profile, but it takes up little space and it's safe to LEAVE EVERYTHING ALONE.

On the local folders, they should have been in the old profile. However, if you have found them elsewhere, I suggest this:

1. exit thunderbird
2. copy and paste the missing folders you found into the active profile at mail\Local Folders. Check first to be sure that won't overlay anything. Do not copy the whole profile as everything is working except for those missing local folders.

Regarding the startupcache, I suggest deleting the contents (I just did it myself to confirm no harm.) Thunderbird is basically stupid, which is highly desirable. For the most part, if it finds a missing file, it creates a new one.

Thanks, david, that appears to have worked well. I did delete the startupCache files and they were re-created. I ended up overlaying everything in the "2jvbyj1c.default" Profile folder with the old data (several cache folders plus the Local Folders files, to make sure everything was in sync. Spot checking shows all in order, and new email still working. Whew!

As far as the Local Folders not being under the Roaming profile, my guess is Tbird or Windows handled things differently in 2014. Thanks again.

We can improve the standard instructions to remind users about custom locations.

As far as the Local Folders not being under the Roaming profile, my guess is Tbird or Windows handled things differently in 2014. Thanks again.

Nothing has changed with respect to Local Folders.