Time after time, email marketing has been shown to deliver stunning results in the hands of savvy promoters. However, it’s a channel that’s had to evolve to keep up with changes in the online landscape.

In particular, email is now largely a mobile medium, with an estimated two-thirds of messages being read on a device rather than a desktop. If your campaigns don’t take this fact into account, they won’t ever return the results they could.

How can you make your marketing emails mobile-friendly, so that they’re widely read rather than instantly swiped to the trash? Here are the seven most important factors to consider.

1. Keep the Subject Line Short

The subject line is the first thing a recipient sees when your message lands in their inbox. On a small screen only a few words will be displayed, so you need to make them count.

If your subject line doesn’t hit home immediately, your message is more likely to be deleted than opened. Don’t waste precious characters with branding or fluff, just get straight to the point with an enticing hook.

2. Craft a Compelling Header

The same need for directness goes for the first line of your email, which in most email clients is displayed by default under the subject. Make this a concise summary that draws the reader in, and don’t waste the space with welcomes, introductions, or scene-setting.

3. Use Careful Personalization

Research has repeatedly shown that personalized emails are more likely to be opened than generic ones. Catching the reader’s attention with this technique is even more valuable in the mobile world, where a swipe to the trash is almost a reflex action.

Something as simple as addressing the recipient by name is almost standard practice, yet still produces results. If you have the data available, you could make an even greater impact by referring to the reader’s browsing or purchasing history.

However, always use personalization with a light touch. It’s easy to overstep the mark and come across as creepy and intrusive.

4. Keep a Tight Focus

Long, in-depth emails may work on a desktop where a newsletter format can be effective. But for a general mailing that’s likely to be opened on a device, stick to a single central point with just one powerful call to action (CTA). In the fast-moving mobile world, too much choice kills action very effectively, so don’t try and make a single email achieve too much.

5. Give the CTA Some Space

Also, don’t let your single CTA be lost in the clutter of a small screen. Lay your email out with plenty of white space so that it’s easy to see the CTAs – and just as importantly, so that it’s easy to click on them.

6. Simplify Layout

The same thinking applies to the overall layout of your email. Don’t try to pack too much content into the message, and discard any unnecessary eye candy or fancy formatting.

Stick to a single column of sparse text, including bullet points and clear images where appropriate. Your email needs to be easy to scan while still packing the content punch you need to produce a conversion.

7. Test on Mobile Email Apps

Most mobile users read email on dedicated apps rather than through web interfaces, and these apps can have their own display quirks. Make sure you test on as many app flavors as possible to verify readability, including the standard Apple and Android offerings as well as the second-tier players such as Samsung Mail and Outlook Mobile.

Although the younger upstart social media hogs much of today’s marketing attention, email remains a workhorse that can deliver amazing results. However, if you’re not optimizing your messages for mobile, you’ll be missing out on most of its potential.