A bipartisan group of lawmakers have reintroduced the Email Privacy Act, a bill that would curb law enforcement’s warrantless searches of email stored on third-party servers for over 180 days.

Microsoft’s lawsuit against the U.S. government for the right to tell its customers when a federal agency is looking at their emails is getting widespread support by privacy advocates. For many, Microsoft’s stance lends an important and powerful voice to ongoing efforts to reform the Electronic Communications Privacy Act that is at the heart of...