'''Pop mail accounts:''' A simple to understand process. Pop mail accounts can only access the server Inbox and download mail not previously downloaded to your pop mail account Inbox. Usually, after downloading, the copy is deleted off the server, but account settings can change this to leave a copy on the server, but Pop mail accounts usually have a smaller quota allowance, so the server emails would need to managed. There are settings in your mail account to eg: delete anything older than xx days or remove off server when you delete them. Pop mail account downloaded emails are stored on your computer in the Profile folders. There is no synchronising between server folders. You can view them if offline. Perfectly suited if you use just one computer to view emails. '''IMAP mail accounts:''' ....are not like Pop mail accounts, so you may find the methodology somewhat different. IMAP mail accounts show a remote view of the folders on the server. You subscribe to see those folders. Headers are downloaded and when you select an email, that email is downloaded to a temp cache. You cannot see emails if you are in offline mode. These emails are not stored in your TB profile on your computer, they are stored on server. If you synchronise subscribed folders, then a copy of the server folder is downloaded into the Thunderbird profile folder as an mbox file and you can see those emails if using offline mode. These folders continue to synchronise to update the server when you make changes eg: move or delete and also if you get new mail on server, it will update the folder in Thunderbird. These emails are stored on the server, but a synchronised copy is stored in your Profile folder. The folders in Thunderbird and on the server are essentially, one and the same. Anything you do either via Thunderbird or via webmail will effect the same folders on the server and then be shown in Thunderbird. IMAP mail accounts usually offer alot more space on the server because they expect you to save emails on the server. Perfectly suited for those who access the server from different computers and other devices like a phone. But you can also use Imap if you use one computer. '''Local Folders:''' 'Local Folders' is a default mail account in Thunderbird. It contains your Outbox. You can move emails from both Pop and IMAP folders into any folders you create in 'Local Folders'. These emails will be stored on your computer in the Thunderbird Profile. They are not effected by any IMAP server. Local Folders mail account does not synchronise with anything. You cannot move a 'folder' from a Pop mail account to an IMAP mail account. The pop mail account folder is only in your Pop mail account in your Profile on your computer. It is not on the server. You can create folders in IMAP mail account or via webmail. You will need to subscribe to see them. If you are wanting to remove the Pop mail account: You can move emails into Local Folders as an alternative storage. You can move emails back onto the server from Local Folders into IMAP mail account folders, but as these emails will be being put back onto the server, you may discover all the dates may change to reflect the new date they arrived again on the server. This might not be desirable. The point of IMAP mail accounts is the emails are stored on the server and you get access by subscribing to see folders and synchronising to download a copy. You can stop synchronising any or all folders to stop getting a copy on your computer and just allow subscribing to download to a temp cache. Tools > Account Settings > Synchronisation & Storage At the top of the page, 'Keep messages for this account on this computer' should be checked if you want to synchronize messages between your local system and your mail server. If this option is un-checked, you can specify individual folders for synchronization or have no synchronising. See info: * https://support.mozilla.org/en-US/kb/imap-synchronization '''Message Filters:''' ''re: I have many message filters that take emails from my inbox and move them directly to the folder where they belong.'' You can apply the same Message Filters used in Pop mail account to the IMAP mail account, but note that you need to have those folders already created on the server. To copy Message Filters from one account to another: Make hidden files and folders visible. * http://kb.mozillazine.org/Show_hidden_files_and_folders In Thunderbird: * Help > Troubleshooting Information * click on 'show folder' button * a new window opens showing your Profile name folder. You should see both 'Mail' and 'ImapMail' folders. * Close Thunderbird now - this is important. * Click on 'Mail' folder * click on Pop mail account * Locate this file: msgFilterRules.dat * right click on file and select : 'Copy' * Go back to see Profile name folder * Click on 'ImapMail' folder * click on imap mail account * Paste the msgFilterRules.dat into this account. * Restart Thunderbird ''re: I want to switch to IMAP and keep all that mail local, not syncronized.'' Having said all of the above, you need to ask yourself why you want or need to change to IMAP because your expectations seem to be different. The point of Imap is that you keep emails on server. Only a copy is put into the TB Profile - local copy on your computer - if you synchronise and it is a folder that continually synchronises. Otherwise you can stop synchronising, but then when you exit TB, the temp cahe is cleared. So emails are still stored on server. Moving IMAP email into Local Folders is no different from Pop, but you still have to link with server to get the emails as they are not stored locally.