Brad Knowles said:

Obviously a few additional enhancements would be necessary, such as cryptographic signatures on return receipts and classification labels (as two examples, there may be more), but MOSS is my current best yardstick for measuring just how well a secure email standard really is integrated into MIME, with the absolute minimal amount of disturbance to the existing MIME standard (and thus, making it the most "native" MIME implementation of a secure email standard).

Both the PGP and S/MIME specifications propose the use of security multiparts -- how come these don't rank as highly as MOSS in your view of how well they are integrated with MIME? Blake