I understand that the 4th amendment protects citizens from unlawful searches. I've also read that email may or may not be protected by the 4th amendment or at least be protected enough that a search warrant is required to access the contents of an email. But how would a search warrant of an email not be a over-broad "general search"? For example a search warrant can't say "Take all papers in the provided location" because the term "papers" is far too broad. How would email be any different? A content provider couldn't screen email for content before releasing the information either. How does the law handle such caveats?