This always puzzles me. You have an account. It has folders. These folders have messages in them. If you remove an account, surely everything in it (folders, messages) has to be removed. Where else would all those folders and messages go to? Was it POP or IMAP? If POP, you're in luck. Or maybe. When you delete the account, it doesn't have anywhere to show the data that was in that account. So it stops showing the data. But it is still there, UNLESS you ticked that box to remove all data when removing the account. You could move the stored messages to Local Folders to recover them You'll need to do this by opening your profile in your file manager and moving or copying the relevant folders. They might be a bit tricky to identify. If the account used IMAP, it's not quite so clear. If you haven't actually closed the account, your best bet would be to add it in to Thunderbird again. If your intention is ultimately to close the account move all the messages in it that you want to keep into Local Folders. If you have closed the account, then it's the same advice as for POP; move the account's folders into Local Folders.