I am not understanding your question, since new mail is downloaded to thunderbird from the internet, not from local folders. It is possible to have new mail stored in local folders. Maybe, if you add more information, some suggestions may be offered. thank you

It was a thing, since I copy the thunderbird , especially since I copy the .thunderbird/<sccount>/Mail/Local\ Folders/ to other computers.

thunderbird used to scan local folders so I could see "new" mail instead of going downstairs.

I can see this question will die in forum :-(

are you talking about movemail that was withdrawn some two years ago and only ever worked on Linux systems.

no addons other than import/export, and that is already installed

It is not clear what you mean by "scanning" local folders. What exactly do you want Thunderbird to do with local folders?

New messages arrive in inboxes. Why are you expecting new messages to appear in local folders? Are you using message filters to move new messages? Why do you put the word "new" in quotation marks?

What does all this have to do with copying local folders from one computer to another? With not having to go downstairs?

when I rsync the original "local mail" folders from host machine, the 2nd machine, all mail is already in their filtered folders.

Before I started from scratch, booting the 2nd machine, thunderbird would show where the new email was. Now, nothing shows up.

The "office" is downstairs, on the opposite side of the house. It used to just scan. now it doesnt'

when I rsync the original "local mail" folders from host machine, the 2nd machine, all mail is already in their filtered folders. Before I started from scratch, booting the 2nd machine, thunderbird would show where the new email was. Now, nothing shows up. The "office" is downstairs, on the opposite side of the house. It used to just scan. now it doesnt'

Apparently, you installed Thunderbird on a second computer and you copied local folders from the first computer to the second computer. Now Thunderbird on the second compuier has local folders from the first computer, as you wanted, but it is not fetching new messages, and you would like it to fetch new messages. is that right?

If it is not right, would you please state exactly what you did and exactly what you want?

more or less correct.

I originally copied the whole $HOME/.thunderbird/ so configuration wasn't necessary

I then rsync the $HOME/.thunderbird/*.default-release/Mail/" from computer 1 to computer 2.

Previously, computer 2 would scan the mail directories and show new email

I understand better. You don't want Thunderbird scanning folders; you want rsync to scan folders and synchronize them. And you don't want just local folders scanned and sync'd; you want all your message folders sync'd, including inboxes.

If you have IMAP accounts, then it is simpler to have the second computer get mail from the server. Then you would sync only local folders. If your local folders are not huge, you could move them to an IMAP account and sync them through the server too. I believe that you know all this already. Is the second computer not connected to the internet?

If you have POP accounts, I don't know the best approach.

I do not know if rsync and Thunderbird work well together.

In any case, unless I misunderstand, your question seems to be about how to get rsync to do what you want. I am not seeing a problem with Thunderbird that I can help with.

incorrect, I rsync to get the latest downloaded, from computer 1 to computer 2.

i want thunderbird to re-scan the local mail folders when starting up, for new mail

A saved search folder can probably do what you want or come close it.

maybe, but don't see how it would see new messages, unless there is a way so search by date.

no i have not looked into that

Well, look into it then. Saved searches can find new messages, unread messages, messages by date, etc. It is the only function like "scanning" that I can think of. If this isn't what you want and what will meet your need, then I still have no idea what kind of "setting" you first asked about or what apparently used to work for you ("it was thing"). Maybe Matt was right about an add-on.

It does work, though not elegant