Pop mail accounts can only get access to the server 'Inbox', so they can only download whatever is in 'Inbox', they cannot get access to any other folder on server. Either of the following methods is ok. Options: '''IMAP''' If you currently have imap mail account, you could synchronise folders for offline use. This will get an up to date copy of emails into your Thunderbird Profile mail account. If you can select and read email content in offline mode you have a copy in the Profile. Then in offline mode (stops further synchronising making sure nothing is being uploaded whilst you are moving stuff) select a batch of emails (not too large). Use right click and 'Copy to' and select a folder in your 'Local Folders' mail account. It might be a good idea to create some folders in 'local Folders' ready to receive emails. When all emails have been copied into 'Local Folders' mail account, these copies are not linked to imap mail account, they are stored in your profile and therefore it would be wise to create a backup of your profile folder name. You can then go back to online mode. You should still be able to read emails in Local Folders. Whether you choose to delete the imap mail account just yet is up to you. '''POP''' This will involve more moving of emails but achieves the same result. Create a pop mail account - you do not have to delete the imap one just yet. Make sure the pop Account Settings > Server Settings say to 'Leave messages on server'. You could set up a Message Filter on the pop mail account which when getting new mail will 'match all messages' to perform this action 'Move message to' and select a folder in 'Local Folders' or do the moving manually. Download everything that is currently in the server Inbox. In thunderbird, move those emails into a suitable folder in 'Local Folders'. In 'Local folders' mail account create a folder called 'Old Sent' When done, if you set up a Message filter, access it again and change the move to folder name eg: Old Sent Logon to webmail account via a browser. Select a folder eg: 'Sent' and put a copy of each sent email in the 'Inbox' In Thunderbird, use 'get Messages' on pop account and all copies of sent emails should download and get put in the 'Local Folders' 'Old Sent' folder. Repeat that process for each folder you have on server which has emails you want to keep. The end result being you get copies of all emails into 'Local Folders'.