My company's internal mail goes through gmail so I decided after recent news to setup GPGmail and s/mime. I identified a couple of usability issues, which wher

My company's internal mail goes through gmail so I decided after recent news to setup GPGmail and s/mime. I identified a couple of usability issues, which where fixed. I'd say all in all its very good. Regardless if you believe or care about the NSA issues, simply the idea of routing clear text email through mail exchanges, and advertisers should give you enough reason to follow the few steps it requires to generate a key, and start encrypting and/or signing email. Except for post cards we don't do this with our regular mail, so why are you ok with it with you email (and your email is far more machine readable). GPGMail is not quite Grandmother ready, and unlike s/mime it doesn't really have an incremental value[1], but it is far more secure, and very easy to use once setup. Plus the other tools in the toolkit are useful for general encryption. s/mime is another option, here are some pros and cons: s/mime pros integrated with many mail apps usually plays nice with mailing lists (adding a footer doesn't invalidate a sig) works on iOS devices (perhaps others?) has an incremental value even before all your contacts are using it[1] s/mime cons based on a certificate authority model cost money depending on the cert you get requires a 3rd 'trusted' party does not seem to be secure in some respects: (web cert generation, no rules regarding sigh/encrypt/sign[2], does not make use of a certificate request so anyone who has even momentary access to your email can generate a cert to masquerade as you) your identity is associate with your email address not you (you will need certs for each email address) -- GPGmail/tools pros Based on web of trust instead of CA (web of trust is not required) You can revoke your key if it is compromised Based on you not your email, so you can use the same sig with any email address You can even associate your picture with your key Optional Anonymity Strong cryptography Use the same keys for non email encryption Free GPGmail/tools cons Less widely integrated. Does not work on devices yet. May break email lists (adding footers may change the sig, I haven't tested though) Can't help much until your have other people to use it with. [1] With s/mime you can sign email documents even if your friends don't have s/mime that can still see your signature is validate. [2] See the answer by Adam Liss (not the accepted answer) for the security issues http://stackoverflow.com/questions/13512026/how-to-check-if-encrypted-s-mime-message-is-also-signed-without-decrypting-it http://stackoverflow.com/questions/13512026/how-to-check-if-... [Edit: formatting]