Here's a message for marketers – emails deliver leads and sales, according to a recent report from Epsilon and Buddy Media. Businesses planning their campaigns should consider that fresh content seems to catch the most clicks.

The study of more than 7 billion email messages across industries indicates that email marketing is holding its own in an increasingly social marketing landscape. Epsilon reports that open rates hit 23.3 percent in Q1 2011, demonstrating quarterly and annual gains. More than one-third of the industries represented in the study saw at least 5 percent gains in open rates last quarter.

Email engagement also made gains, which marketers should note is also good for SEO. (As Brafton reported earlier this week, inactive subscribers can hurt Google rankings in the post-Panda search landscape.) Epsilon reports that click-through rates hit 5.9 percent, showing growth over 5.1 percent CTRs in Q4 2010. Plus, click-to-conversion rates increased 26.5 percent year-over-year during Q1 2011.

The study concludes that “relevance is a critical factor” for any successful email marketing campaign, and fresh high-quality content is core to making content valuable to recipients. While just 1.3 percent of marketing emails were primarily editorial in nature, these messages boasted some of the highest open rates (24.26) and click-through rates (7.5 percent) in the study.

With this in mind, marketers will want to plan their content strategies with fresh email newsletters in mind. News content marketing naturally lends itself to email marketing, as the Pew Research Center for the People and the Press reports that 12 percent of Americans regularly look for news headlines in their inboxes.