On Sun, Aug 25, 2013, at 11:12 PM, Bill Stewart wrote:
You might be able to run an email service that scans inbound email for an X-PGP-Encrypted: header, and if it sees "From:" or "Subject:" first, bounces the email with a 503 or 550: "Sorry, Encrypted Email Only, Get PGP at www.pgp.com", but that's really more annoying than just using Gmail with a user name pgp-only-johndoe43@gmail.com.
I like the concept, but not with the ad for commercial PGP at the expense of GnuPG and others. Though I think the following poster who suggested scanning the email itself for the PGP identifier might be more useful and less prone to being fooled by someone who just puts the header in there without actually encrypting. Also, headers don't have to be in a specific order, it's possible that "From:" or "Subject:" accidentally get moved ahead of "X-PGP-Encrypted:" by mistake and that would result in a false bounce. -- Shawn K. Quinn skquinn@rushpost.com