Is there a way to import email from the raw email files?

Those folders contain e-mail stored in Maildir format. Wikipedia has a list of e-mail readers that can directly read e-mail in that format, which include the popular KMail and Evolution mail clients.

Most open-source mail server software also supports that format so it should be easy for your current e-mail system to import them. The folks over at Server Fault can help you with that if you give them specifics.

What email client/OS are you using?

See if you can import them as per Patches advice. If that does not work, you may end up having to do it manually.

In that case, rename one of the files and giving it an extension of .EML, then open the file. Your default email client should run and open the file, displaying the email message. Once you’ve confirmed that it works, you should be able to drag-and-drop the .EML file into your email client and view it as normal. Then you can iterate through the folders, renaming the files to give them the extension, selecting them all, and dropping them into the client. Then you can sort them, or sort them as you drop them in.

Of course you will want to help reduce the amount of manual work, but for example, using a batch renaming tool (I like Cylog’s WildRenname). Also, you could reduce the amount of manual work by using a macro tool to automate repetitive actions like key presses or mouse clicks.