After seemingly taking ages to do anything, Congress is at last moving forward on better email privacy safeguards. A House committee has voted unanimously to approve the Email Privacy Act, a bill which would require that federal officials get a warrant to access email (and any other digital communication) if it's older than 180 days. The measure still has to make the usual rounds through legislative and executive branches before it can become law, but it already has the backing of the majority of the House. Barring surprises, there's not likely to be much resistance.
The bill as-is won't make everyone happy. Amendments to the act would remove the requirement for a warrant against the target of an investigation; it'd only require serving a warrant to the email host. Subjects wouldn't necessarily realize that a search is taking place. That's not enough to deter tech companies supporting the bill (including Facebook and Microsoft), but it's clearly a compromise. Also, the Justice Department has claimed that the 180-day distinction is arbitrary. If you need a warrant for an ancient message, it argued, you should need a warrant for something new.
With that in mind, the Email Privacy Act is still better than what the US has today. Right now, the feds only need a subpoena to get communications -- they're not subject to the same judicial monitoring as they are with warrants. The would-be law could reduce the chances that investigators collect more information than they need, and keep your conversations under wraps unless there's good cause to suggest that something illegal took place.