Because that is how SSL works. I don't understand your question. Your bank uses one SSL key as well. Google has one SSL key for their homepage. It is not possib

Because that is how SSL works. I don't understand your question. Your bank uses one SSL key as well. Google has one SSL key for their homepage. It is not possible for a top level domain to have more than one SSL certificate. Are you asking why SSL works the way it does? You'll have to talk to the people who wrote the RFC. SSL is what is used to protect communications between a client and the Lavabit endpoint. Once a request is inside the lavabit network other security measures are used. For example, each email message is signed using the account key for a given member, the account key is itself encrypted with the members password. The only way to decrypt a message is with the account key and the only way to decrypt the account key is with the member password. If you lose your password, your mail is gone forever. The feds had access to snowdens encrypted emails, but they had no way to decrypt them without his account password and the only way to do that is with snowdens personal password, which is why they wanted to sniff unencrypted traffic (to snag his password en route to the lavabit server). I've simplified a few things but this is a rough overview of how his system is designed.