To avoid unnecessary work, quit with the filing system.

Gmail and other clients allow you to set up filing systems to allow users to better organize their inboxes. But it can just get in the way.

"Email folders are categorically the worst way to look for email messages," says Alex Moore, CEO of the email management service Baydin, the company behind the Email Game.

A folder system is self-defeating, he says, because even if you make a bunch of great folders, you might not recall where you put a given message. A search is way faster.

To save you time and get your messages read, write shorter subject lines.

Marketing company Retention Science did an analysis of email replies and found that "emails with subject lines containing six to 10 words were the most effective at getting the recipient to open them up."

As we've reported before, there's a science to subject lines.