DKIM-Verify is a software application that can provide DKIM verification for non-DKIM-aware MDAs. Using DKIM-Verify, which functions as a "wrapper" for the MDA, mail originating from and destined for the local domain can be verified. In addition, DKIM-Verify can integrate with mailing list software to provide verification of messages received for later distribution.
Mover is a system designed to move mail while eliminating as much metadata as possible. In fact, it eliminates virtually all metadata, except for the order and possibly the time that a message arrives at a given site. Addresses are encryption keys. The encrypted messages are sent to all mover locations. The intended recipient uses their key to decrypt the message.