On 26.08.2013 06:12, 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",
If you're crazy enough to do so, here's a mail filter that rejects non-PGP mail. Currently, it simply scans the first 5000 characters for "-----BEGIN PGP MESSAGE-----", and, if not there, rejects with a 550. https://github.com/moba/pgpmilter We will use it soon for the onion.to Tor mail gateway: https://lists.torproject.org/pipermail/tor-talk/2013-August/029464.html --Mo
