disappearing account folder in thunderbird

Today I set up 2 new mail accounts xxx and yyy on thunderbird using ' tools->account settings->add account'. they both use the same pop [mail.btinternet.com] as the main account and are, in fact, sub accounts of the main account on the BT server. Both new accounts showed up with inboxes on the LH pane. However, after closing TB and restarting it, the folder for yyy was still there with its inbox but the folder for xxx had disappeared along with its inbox [in the LH pane]. If I click on tools->account settings, both xxx and yyy are still there. How do I recover the inbox of the disappeared account?

The only thing of which I am aware that might have confused the issue was that TB had apparently gone to sleep while trying to download messages for the 2 new accounts.I therefore closed TB and restarted it.

 

try View, Folders, All

 

I always use View Folders All, . It displays all folders except the folders for one of the 2 new accounts. i.e. It shows all the folders for all previously working accounts plus for one of the new accounts and not the folders for the other.

 

For me, the set up has been moronic, at best, as Thunderbird gives me a slew of incorrect servers, so that I have to delete their incorrect folder, and create one, manually.
In theory, if your account was set up correctly, Tools|Account Settings|Server settings|Local Directory under the account name should point to the correct folder.