Is this a pop or imap mail account ? Is the left Folder Pane completely empty or does it show the mail account name and nothing else? If imap and you can see the name of the mail account: Make sure you have subscribed to see the folders: * File > Subscribe Make sure these settings are selected: via Menu bar: 'View' > 'Folders' > 'All ' OR via Mail Toolbar: 'Menu icon' > 'Folders' > 'All' also 'View' > 'Threads' > 'All' Make sure nothing is selected in the Quick Filter Bar. If the above does not work : In Thunderbird * Help > Troubleshooting Information * click on 'Show Folder' button a new window opens showing contents of profile name folder * '''Close thunderbird now '''- this is important Look for and delete these files : * foldertree.json * session.json Note if you cannot see any files then you may need to make hidden files and fodlers visible to see them: * http://kb.mozillazine.org/Show_hidden_files_and_folders * close window - top right X * restart Thunderbird report back on results.