The 'quota' is refering to the account on the server. So the gmail server Inbox has used 77% of it's allowance. As the gmail imap account Inbox folder can only display what is stored on server, it will also show same quota. Even if you download full copies of email and not just the headers, you cannot consider any imap account folder as a separate independent copy because the folder synchronises with the server folder and can only display what is on the server. However, downloading full copies does mean you can create a backup. The 'Local Folders' mail account in Thunderbird is not connected to any server. Emails stored in 'Local Folders' are stored on your computer and are totally independent of any server. I suggest you do the following: I'm assuming you have downloaded full copies. Go into 'Offline mode' - I advise this because if getting lots of copies of emails into 'Local Folders' then it's easier and less risky if folder is not able to synchronise with server for the duration. If copying only a few then it would not really matter, but always check you can read the copied email before removing the original from the imap folder. * Menu app icon > File > Offline > Download/Sync Now * Select 'Mail Messages' * Select 'Work offline once download and /or synchronisation is complete * Click on 'Select...' button * Make sure all folders are selected and click on ok * Then click on 'OK' button to proceed. Once in Offline mode: * In 'Local Folders' mail account, create some folders that have suitable names for storing/organising emails. Please remember, emails are stored in mbox text files appended one after the other, so one folder in Folder Pane is really one text file. It is less risky to have several folders and organise emails accordingly eg: Family, Friends, Orders etc In imap folder: Any email which is important - right click on batches (not too large) of highlighted emails and select 'Copy to' and choose the appropriate folder in 'Local Folders'. Advise you use 'Copy to' and Not 'Move to' because if something goes wrong then you can repeat the process. Check the copied emails - select random emails to double check you can read the contents, so you know you have a good copy. If copy has been successful, then you can delete the original from the imap folder. Repeat this process until you have completed the task. Then compact the imap account folders to fully remove all traces of deleted emails. Now is a good time to create a backup after all you still only have one copy. * Menu app icon > Help > More Troubleshooting Information * Under 'Application Basics' - about half way - Profile Folder - click on 'Open Folder' A new window opens showing contents of 'profile name' folder. * Exit Thunderbird now. * Go up the directory 3 levels until you are in the 'Roaming' folder. * Copy the 'Thunderbird' folder to an external drive as a backup copy. Restart Thunderbird and it will automatically start in Online mode. Thunderbird will synchronise with server and emails will get deleted off the server. You should see all the copied emails under 'Local Folders'.