Email marketing on mobile phones has been tottering on the brink of opportunity. Some e-marketers may have already embraced it because their customer base are a very mobile bunch. Others have taken a ‘wait and see’ approach, shelving it as something for the future.

Only a couple of years ago, mobile e-marketing still seemed very visionary. In fact, it was only high-tech companies, or those on the cutting edge of technology that dealt with mobile email marketing. However, times have changed, especially with the pervasiveness of the BlackBerry and the advent of the iPhone. The power of the Web is now on the tip of mobile users’ fingers. While these are exciting times for both mobile users and well as the mobile industry itself, there are definitely some major hurdles to cross. One of the mobile’s biggest challenges will be in forcing e-marketers to ensure their email marketing program is completely customer centric. For your mobile email marketing campaign to take off and not crash land, it is crucial that marketers listen to and understand what their customers want and require, for example, in what format do they really want to receive their mobile email? Before you run off and start your mobile email campaign, it is also important to clearly understand exactly what makes the mobile different:

The Platform

The first major difference can’t be more obvious than the platform itself. Instead of a screen that measures 13 to 21 inches on the diagonal, you have maybe 2 to 4 inches. E-Marketers that thought that the email preview pane was restrictive therefore have to be even more creative here.

Content rendering

Mobile devices tend to vary quite a bit in how they render content. Although BlackBerry has moved into the HTML content space as well, an immediate revolution when it comes to content rendering is still not in the books. For e-marketers who still want to consider text, it usually renders when on most mobile devices but it is still vital to optimize text messages for the smaller screens.

Always Available

Your message recipients might not be living their lives through their mobiles just yet, but they most likely use their phones to surf through their inboxes when they're away from their desktops/keyboards. This enables them to always be connected, allowing them to always be on top of important emails.

Optimizing your email message for Mobile readers

The good news is that if you have already optimized your HTML messages to compensate for blocked images and the preview pane of email systems, both of which are default settings for most desktop and Web email clients, your messages will most likely show up better on most mobile platforms.

Despite this, all e-marketers considering going mobile should take a couple of extra steps to make messages even more mobile-friendly:

Reformat text

Always offer a text option as an alternative to HTML for all your message recipients. You can send this version to your mobile readers, but bear in mind that you might also have to reformat it to make it show up better on the smaller screen.

Most text messages have 60 to 80 characters per line. Mobile platforms will show 20 to 40 characters in 12 to 15 lines per screen, depending on screen width and type style.

Desktop-friendly line lengths can create long paragraphs in the mobile reader. If you use typographic devices as copy separators that also run 60 characters, for example, you'll give up four to five lines on the screen for something that adds no value.

Rethink tracking URLs The same advice as above goes for URLs.

Tracking URLs can also consume four to five lines per screen. If you can, use a simpler URL, even if it means sacrificing some tracking ability. Long URLs can result from automatically reformatting HTML copy into text, so your text version may need some hand-tweaking in order to render better on all platforms.

The briefer the better

Message size must come down whether you send in text or HTML. Messages over a certain size – even as small as 12KB -- risk being cut off halfway through. In many clients, your reader can opt to click a button that will call up the rest of the message, but why risk them not doing so, and especially, deleting your message immediately? Your message content should therefore be re-thought. Long sentences in long paragraphs force more and more scrolling. This also can be a barrier to conversion or another source of frustration for readers.

Validate your Web site

Is your Web site mobile-friendly too? Probably not, if you haven't had it redesigned specifically for mobile applications. If you have to send readers to your Web site to get the most value from your email marketing, better make sure it will also render on their devices. You can check it easily by using a new validator developed by the World Wide Web Consortium: http://validator.w3.org/mobile/.

How to ensure more Mobile-Friendly Emails

Include a mobile option on your subscription or registration page. Track how many users check this option.

• Add a mobile reference to your online-version link in your message copy.
• "Above the fold" becomes even more crucial on the mobile screen. If you must keep boilerplate elements such as an admin center at the bottom, link to it near the top so that readers will know they need to click to download it.
• Keep your message short, and give readers a reason to save it for later to view in their desktop clients.

Test before sending. You should be doing this anyway, but mobile devices add another platform to the mix. Don't assume that because it looks good on your BlackBerry or iPhone, it will show up that way on all Web-enabled phones.