how do I transfer my outlook 2007 pop3 mail box into a new Imap account?

As far as I know, IMAP by itself doesn’t support this. Your IMAP email provider might provide a service like this, but I doubt it.

Why do you want to do this? Have any more information on your problem?

The reason I need to do this is the following. The emails were retrieved from an IMAP account and are now in my Outlook 2007. The IMAP account is on a web server that is closing down. I’ve set up a new IMAP account on the new webserver. This account will then ofcourse be empty to start out with, so I would like to put the emails back and start using the account as before. This brings me back to the initial problem, how do I upload these emails back into the IMAP account. I hope there is a solution. Thanks!

Well, it depends on what you want to do with the old emails. If you just want to have them around for archive purposes, you can just download all of them into your email program, keeping them in separate mail boxes. I don’t know how Outlook 2007 handles IMAP, but if it’s a POP account this should be the default behavior, meaning that when your old email provider shuts down you will keep all of the emails you’ve downloaded from that account, and you can use the new account while keeping all of the emails from the old one on your own computer.

Would that be a good solution for you?

(This would make it even more important for you to do regular backups, as all of your old emails would only be on your computer, and not stored anywhere else)