This should do it: - exit thunderbird - copy the desired local folders to the other drive - start thunderbird - click to 'account settings' and scroll to Local Folders - click the Browse button at 'local directory' and change to the new location - now you can delete from the Mail\Local Folders folder

Thank you but where in account setting do I find local folders?

Rgds

And where on my C disk are the local folders?

A simple way to locate them is to click help>troubleshootinginformation, scroll to 'profile folder' in left sidebar, click 'open folder' and you will be in the profile. Click the Mail folder and then you will see local folders.

Thank you this locates the local folder.

Now, how do I tell ThunderBird where the new llacal fomders are after the move?

Rgds

That is in my first response, above.

Your response says: "click to 'account settings' and scroll to Local Folders" butn I cannot see Loacal Folders in account settings.

Scroll down left side bar in account settings page. Local Folders appears normally below the accounts. If you cannot see it, please post a screenshot. Thank you.

Found!

Local Folders was not visible but I had to scroll down in the list of accounts to make it visible.

Problem solved, thank you.