Savvy email marketers know that emails aren't being read just at the office anymore. When people are stopping at lights or waiting in line at the store, they now whip out their mobile devices and check their email. So, to keep your email communications engaging, you need to focus on designing for, well, everything. Sound like a tall order?

Don't worry---email was practically made for mobile devices, says Loren McDonald,a MarketingProfs University instructor and vice president of Industry Relations at Silverpop. In his Email Marketing Essentials talk, McDonald offers these quick tips for creating email newsletters that shine on mobile devices:

1. Write snappy, engaging pre-header text. It's the snippets of info that show up before anything else does. It's the first peek at your content for the reader, so make sure you don't waste their attention. Use it, and use it well.

2. Offer clear calls to action in different formats. "Using different language and creative, buttons, and things that all direct people to the same call to action is important," says McDonald. Folks may completely overlook a graphic element that's a call to action, but will notice a link instead (and vice versa).

3. Use alt attributes (tags). Give people a quick sense of what's behind an image by providing tags. Not every email client recognizes it when images are turned off, but it's still worth using for those email clients that do read them.

4. Incorporate text over images. Make sure the text in a link shows, so that something is still in front of your readers' eyes, even when images aren't being loaded.

5. Design for the touch. McDonald says, "Our fingertip is replacing the mouse." Keep that in mind by designing emails with links and blocks of text that are easy to touch. If your links are too close together, that might be fine for a mouse-click, but it's a different story for fingers.

6. Use scalable fonts and images. Use cascading style sheets (CSS) for mobile devices. "They can determine the size of the screen that the email will render on and then size the images and fonts up or down to be perfect for that device."

Have any other tips you'd add to the list?

To learn more about email marketing, sign up for the Email Marketing Essentials course at MarketingProfs University. You’ll enjoy 11-plus hours of intensive, online instruction by 15 email marketing experts. The course features 14 classes broadcasting live May 12 through 27 and then on demand through May 2012 (in case you miss any classes).