> It's also worth saying that PGP isn't a particularly great cryptosystem. "Modern" PGP predates a lot of important stuff in crypto. But it's a very well studied cryptosystem.

Is there anything available today that you'd recommend over PGP, regardless of usability or ubiquity? e.g., if one has to include crypto inside an internal-use only email product, that requires both encryption and/or signatures - what's an alternative to PGP that would be considered reliable?