Sen. Patrick Leahy, D-Vt., chairman of the Senate Judiciary Committee, has been lining up support among Republicans to bring the measure to a vote before the upcoming recess.
An aide to Leahy told The Hill that even if the vote doesn't take place until fall, there is enough support in the Senate to overcome a potential filibuster and pass the measure.
The bill, which is co-sponsored by Sen. Mike Lee, R-Utah, would require police and other law enforcement agencies to obtain a search warrant to go through email. Current law requires only a subpoena for police to gain access to email messages more than 180 days old.
The Hill said the law was drafted in 1986, prior to the advent of massive email storage. At the time, it was presumed emails kept longer than six months without being opened or deleted would be considered "abandoned" and not subject to privacy protections.
Although there has been renewed interest in Internet privacy due to the flap over data surveillance by the National Security Agency, there has also been concern in Congress and among federal law enforcement that Leahy's bill could hinder investigations into securities fraud, which is often a civil matter rather than a criminal case.
Leahy contends the Securities and Exchange Commission can get around the issue by directly subpoenaing the companies and individuals under investigation rather than going through Internet companies like Facebook and Google, The Hill said.