Are you sending out your email messages at the best time to get the most opens and responses? Based on email volume between the fourth quarter of 2011 and the fourth quarter of 2012, it's doubtful.According to the Quarterly Email Benchmark Study from Experian Marketing Services, the best days of the week to send email messages to your audience in order to get the highest open rates, response rates, and transactions are Saturday and Sunday when mail volumes are lowest.Timing affects response rates, too. Experian's study found that response rates are highest between 8:00 p.m. and 12:00 a.m. followed by the time period between 12:00 a.m. to 4:00 a.m.Despite significantly higher open and response rates tracked during the times mentioned above, most companies, publishers, brands, and other industry emailers continue to send their messages during business hours, Monday through Friday. Most email (40%) is sent from businesses and publishers between 8:00 a.m. and 12:00 p.m. Another 20% is sent between 4:00 a.m. and 8:00 a.m., and 15% more is sent between 12:00 p.m. and 4:00 p.m. That means only 25% of email volume from these sources is sent between 4:00 p.m. and 4:00 a.m.Many of these companies and publishers are actually sending more email messages than ever during those high-volume times, which simply adds to the clutter in recipients' email inboxes. Travel companies and publishers showed the highest growth in email volume between the fourth quarter of 2011 and the fourth quarter of 2012 (21.4% growth and 14.3% growth, respectively).The study also found that consumers are opening and responding to email messages faster than ever with open rates jumping from 74% in 2010 to 78% in 2012 and response rates climbing from 76% in 2010 to 80% in 2012.The lesson for publishers to learn is simple. If you want your email messages to your audience to get noticed, send them during low volume times. At the very least, test sending your email messages between 8:00 p.m. and 4:00 a.m. and on Saturdays and Sundays. If the Experian study holds true, you should see an increase in open rates and the number of people who click through to read your content (if your content isn't included in its entirety within your email messages).You can see all of the details in the infographic from AdWeek below.

Infographic: Carlos MonteiroImage: Agne Kveselyte