I don't know of any, but that doesn't mean there aren't any.
If one is determined enough, one could make it happen with Mail.app, one way or another.
If Mail.app permits the modification of headers once mail has been read, an AppleScript could do the trick, and this would be the easiest, most direct way.
If not, one might be able to directly modify the message my manipulating the mbox files which Mail.app uses to store eMails, but this technique has several drawbacks and i don't recommend it.
A safer and more robust technique would be the transformation of the header prior to Mail.app reading the mail. This can be done through a combination of procmail, fetchmail, a little shell scripting, the AddressBook CLI tool, and a local pop server. This approach should work with a variety of mail clients, but has some limitations too.