The problem with PGP is that while it keeps the content of your mail exchange secret, it does not protect the information that two persons exchanged emails. So if the investigators have a lead to person A that sells drugs and see that he's communicating with person B that accepts payments, the might just guess what relationship the two have.

Right, that's why you use Tor. PGP provides privacy and accountability. Tor provides anonymity.

Just remember you have to trust the security of the receiving party as well. Make sure not to reveal yourself with the contents of your emails since the other party might not be as disciplined with their tor and pgp use as you are.

Tor doesn't anonomise email :-/ If you want that, look for mixminion or mixmaster. Tor is a low latency mixnet for TCP streams (aka web browsing).

SMTP uses TCP and works over tor just fine. But you can always just use a free web mail account somewhere.

Yes, that's to fetch mail from a server. TorBirdy for instance is a plug in for Thunderbird.

But! If you want to send a message alice@domain.com to bob@otherdomain.com that is not anonymous, unless you take other measures.

Yes. There is a difference between "private" and "anonymous".

Encryption often removes anonymity by tying an identity to keys and to a web of trust.

For that use tor to access your emails and/or use tormail.org which will not be able to disclose that information.

Actually now-a-days it's using an OTR client, since it adds deniability and forward secrecy. I don't know if it removes offline messaging. It's also a lot easier to use and easier to convince your friends and close ones to use it since they only need to flip a switch practically.

http://www.cypherpunks.ca/otr/

@Xylakant then you have to pull an "Petraeus" and just keep the emails unsent in the draft folder. Not sure if this is still a viable option.

People are forgetting that if you use PGP you can post it anywhere

The Petreus incident is sort of crazy for this reason. Here is the head of the CIA, doesn't even use PGP.

There are other mixnets such as Mixmaster and Mixminion that do what Tor does for TCP but with email. They unfortunately need many more people to run nodes.

"The Petreus incident is sort of crazy for this reason. Here is the head of the CIA, doesn't even use PGP."

He's just a bureaucrat, hired after retiring as an Army general. I seriously doubt if he had any personal spy craft training beyond "use this secure computer and this secure phone when you're working on company business, sir. And don't talk about Fight Club."

<tinfoil hat>

The head of the CIA is aware of the methods used to extract information from suspects, and thus wants his information to be easily found if he's discovered, rather than requiring him to be extra-ordinarily renditioned and water-boarded.

</tinfoil hat>

I guess it just shows that anonymous and private communication is still really hard for most people, even though we had the work of cypherpunks trying to help.

Why would they waterboard him if he was willing to give up the keys?