@AC Re: Simple solution
Key escrow is fine in principle, but it's not really escrow if your government is using it to read all emails for "dodgy" content. Don't worry about hacking; every government and agency will want access to the database, so it will be leaked anyway.
A slightly more elegant solution would be for one "trusted" agency under each government to be able to issue keys and use a "secure" local database to decrypt its citizens emails and forward the contents if "appropriate".
Using an unapproved key will lose you your email rights. But it's not all bad news - TXT & 1337 speak and spammers random-word techniques will be detected as secondary encryption, and the perpetrators removed from society.