IMAP isn't designed well for that. You would need to download messages and then copy to a Local Folders folder for each of the IMAP folders. This is because, once you delete a message in a folder associated with the account, the message is also deleted online. To be specific, there is no automatic way. It appears you initially created an IMAP account and now want it to be POP. A possible option (if your goal is to download and delete) would be to download the non-inbox folders once and copy to Local Folders and then delete those folders. From then on, you could use POP for the one inbox.