You know what sets apart the winner emails from the losers that people automatically trash? Subject lines. Flickr/Leo Hidalgo Like me, you no doubt receive a veritable landslide of emails in your personal and business accounts.

Most of us are bombarded by hundreds of email messages every day, adding up to hundreds of thousands of messages that we — and the people we're trying to reach — have to filter through every year. The sheer volume is enough to make even the most organized person want to declare email bankruptcy.

You know what sets apart the winner emails from the losers that people automatically trash? Subject lines: 40 to 50 character sales pitches that convince people to click, open, and read.

Considering the super-brief amount of text, there's an incredible amount of things can go wrong before even getting to the body of the email. Every day, I receive emails with subject lines that are vague, aggressive, too-familiar, or just downright annoying.

If you're having a trouble getting responses from the people you most want to reach — sales prospects, networking connections, former colleagues — take a good look at your subject lines, and make sure none of these are types of messages are slipping through.