The sales people would raise high holy hell if their customers and especially their prospects could not email them without encryption. Same thing for customer support people.

What about all the automated emails that get sent from various systems and servers being run internally? Many of these servers are software bought from a 3rd party and the company cannot easily modify them to send encrypted mails.

So while I agree that encrypted mails are a good idea for companies, it is not feasible to mandate encryption.

Also, another idea on the way public keys should be traded is a DNS-like lookup system for public keys. Once a certificate authority provides a public key to an email address, this key would be shared and forwarded amongst all the authorities in the same way that a domain name is shared and forwarded amongst DNS servers. To go along with this, a new type of key lookup server would be implemented. This server could be run by the certificate authorities, ISPs, or even particular techie people on their linux box at home. The final piece is that email client software should be able to look up any email address to on this server to see if there is a public key registered for it. If so, it can use it for encryption. The user should even be given the choice of whether to use this key automatically when sending emails in order to encrypt them whenever possible.

As more and more people sign up for encryption, this type of system will become more and more useful.

Someone please write a standard for this!