'''To create a top level folder''' * Right click on mail account name in Folder Pane and select 'New Folder' * Enter name of folder * Click on 'Create Folder' '''To create a sub folder:''' * Right click on folder and select 'New subfolder' * Enter name of folder * Check you have correct folder in the data 'Create as a subfolder of:' * Click on 'Create Folder' Please note if this is an imap mail account then the folder does need to be checked that it is subscribed to be seen. Also check the settings are correct for that folder eg: do you want to store/download full copies of emails or only headers? Check settings in 'Account Settings' > 'Synchronisation & Storage' click on 'Advanced' and make sure that new folder is selected for download or not - as required. Alternative for IMAP accounts. Logon to webmail account and create a new folder. Make sure it is allowed for imap - some servers require you select that option eg: gmail In Thunderbird * Right click on mail account name in Folder Pane and select 'Subscribe' * Click on 'Refresh' * Select the new folder * click on 'Subscribe' * Click on OK