Is this a folder in a pop or imap account or in 'Local Folders' account? I'm presuming imap, so tell me different. If imap: Logon to webmail account using a browser. Do you see the old folder or the renamed folder? Do you emails in old or renamed folder? If old name and it contains emails, leave as is, if renamed folder with dot and contains emails then remove that dot, so renaming back to previous name. So you now have old folder name with emails. Back in Thunderbird. Files and Folders will interpret a dot meaning what follows is the extention. In the thunderbird profile folders, emails are stored in mbox files which do not have an extension, so the dot could be not allowing the mbox file to be seen as an mbox file. Hence no emails. In Thunderbird * Help > Troubleshooting Information * click on 'Open folder' A new window opens showing the contents of your 'profile name' folder. * Exit Thunderbird now. * Click on 'ImapMail' folder * Click on imap mail account name folder * Locate the file which has a dot before it. There will also be a *.msf file of same name. * Delete both. As folder with emails in on the server, you should be able to subscribe to see folder and download everything from server. If unsure what to do, tell me what you see in webmail account and post image showing contents of imap mail account folder that contains the mbox and .msf files.