Swamped email inboxes are the No. 1 concern on the minds of most marketers. That’s why cutting through the proverbial clutter is more important than ever.

Here’s a roundup of *what really works* versus *what doesn’t* in email design -- from the subject line to the message body. The cross-niche ideas come from hundreds of Sherpa Case Studies on email, our Email Marketing Benchmark Guide 2008 and relevant data and findings from the email industry and the blogosphere.

-> Strategy #1. Subject lines - long or short?

The length of a subject line remains intensely debated. Choose your side.

Sherpa’s research of our own newsletter open rates has found that shorter subject lines get better open rates. And MailerMailer’s Email Marketing Metrics Report from last fall says subject lines with fewer than 35 characters outperformed longer ones by more than 5% in open rates.

Through frequent testing, Anna Cheliapina, Email Marketing Manager, Carlson Marketing Canada, has found that subject lines over 45 characters get truncated by some email systems, particularly Hotmail and Gmail. These shortened lines can damage your open rates and your sender reputation because they provide a visually displeasing incentive for subscribers to either hit the ‘Delete’ or the ‘This Is Spam’ button.

Carlson’s 45-character rule, thus, is a smart bet, especially when more emails are being read on space-limiting mobile phones. Their advice also jibes with copywriter Karen Gedney’s motto for writing subject lines with both mobile and computer users in mind: “Be brief. Be brilliant. And be gone.”

On the other hand, two other email experts say longer subject lines – but at varying lengths -- perform better:

- Alchemy Worx presented data at MediaPost’s recent Email Insiders Summit that says open rates increase with subject lines in the 50-character and 80-character range. But open rates fall when the length is somewhere in between -- 60 or 70 characters.
- MyEmma also has experimented and found that longer subject lines boosted higher open and clickthrough rates than their shorter counterparts.

More insight: MyEmma’s Suzanne Norman points out that if you’re promoting a specific call to action, shorter is better. But if your newsletter focuses on relationship building and content, a longer subject line might provide a better opportunity to tease the content and get your readers engaged.

Sherpa’s take on the debate? Norman may be right, but test, test and test some more to find out what works best for you.

-> Strategy #2. Design for range of email systems

You simply can’t expect one email design to fit all the major providers. Hotmail is one of the trickiest to deal with because it tends to center all of the copy, which can create a look of disarray. “By doing email testing every week, I notice that [the way email renders in Hotmail] changes about every six months,” adds Cheliapina.

Hotmail’s rule changes become even more sobering after looking at one particular data-point from Sherpa’s Email Marketing Benchmark Guide 2008. It found that MSN/Hotmail was hands-down the ISP that puts the most stock in email content when it comes to filtering. Content made up 68% of why a message got sent to the spam file, leaving 32% for sender reputation.

By comparison, AOL, Gmail and Roadrunner gave 100% consideration to sender reputation and nothing to content. So, MSN/Hotmail’s constantly changing content rules simply makes the already dicey world of email sending a little bit rougher.

Meanwhile, Carlson’s testing reflects other emailers’ MSN/Hotmail issues as well. For instance, LiveNation last year tackled their issues with MSN/Hotmail and, after some homing in, lifted deliverability by 20% and boosted email-driven sales by 143%.

What’s the major takeaway? Again, more testing. It’s critical that you *regularly* pre-test your campaigns in all the ISPs. Your layout needs to render appropriately in every case. It has been a Sherpa best practice for some time, in fact, to set up accounts with all the relevant email receivers/ISPs. Then test the heck out of your rendering and deliverability before pushing “send.”

-> Strategy #3: Design for preview panes

If you’re not already designing your emails for how they look in preview panes, start today.

The Sherpa data is too overwhelming -- for business users as well as consumers:
o 80% of at-work users rely on Outlook, which offers preview panes
o 70% of consumers use a preview pane if their email system allows it

Your email needs to look enticing in that tiny bit of online real estate because so many recipients look at your messages in their preview panes. The look can control the decision to open or delete.

Designing for Outlook can be tricky, though. You have to build emails for recipients to view the most important content on top. For instance, Carlson began putting links on top and saw clickthroughs increase because people immediately explore their options in the preview pane.

How about multiple offers? Building email campaigns for a single offer on a targeted landing page is optimal, but many enewsletters have to incorporate several ideas into each send. In this case, Carlson advises marketers to create a hierarchy of importance for each action item and stack them accordingly.

“So even if you have your Outlook open to preview mode, you will still get the information you need at that point,” says Kevin Manklow, Art Director, Carlson. “And if you choose to scroll down, you’ll get all the fancy [features] from there.”

Need more proof about designing for preview panes? MarketingSherpa’s Email Benchmark Guide 2008 says that a significant 84% of respondents age 18-34 use the preview panes in advanced email clients like Outlook to decide if they want to see the message entirely.

-> Strategy #4. Don’t forget old-school design elements

The old-school HTML design tool known as table cells appears to be making a bit of a comeback. Table cells -- often referred to simply as tables -- can hold various types of information and span multiple rows or columns.

Their inherent delivery advantage lies in the fact that -- unlike Cascading Style Sheet (CSS) designs -- Web mail providers won’t strip the color or text from table cells -- even if recipients have images turned off. The use of table cells has been a key driver behind Carlson’s double-digit lifts in CTRs. They normally use them for the right-hand column in newsletters and for text and color just below the header.

Financial services firm Van City also has seen clickthroughs jump 10% this year after employing the table-cell design tactic. They mix the table cells with CSS images so recipients with images turned off at least get the major part of an offer -- even if they don’t see the high-resolution photo placed by CSS.

Here’s another example from a recent Sherpa Case Study of table cells: Eretailer Legendary Whitetails lifted deliverability by 10.1%, opens by 28.6% and clickthroughs by 83.4% after starting to use the tables. Even better: Email-generated revenue skyrocketed 379.3%.

Marketers should also use color-based table cells to “create the illusion of imagery structure,” says Dan Patreau, Manager, Interactive Development, Carlson Marketing. “We try to bundle [CSS] images all in one section so there is only one section where images are not showing up. The goal is to get one only ‘image X’ instead of 40.”

And here’s a quick tip for your IT person: Gmail often strips colors in a way that distorts your intended design, whether you are using more advanced CSS or HTML table cells. Yahoo!, on the other hand, is not as sensitive, but it does strip some colors when using CSS.

-> Strategy #5. Copy at the top serves mobile readers

Placing meaningful copy at the top lets viewers get a taste of your offer no matter what kind of device they are using to read it.

Readers who scroll emails on their BlackBerry, for one, will be very appreciative of your efforts. And some good news from MacMail is that people viewing email on iPhones can automatically see images. But keeping regular computer users in mind also is extremely important, Cheliapina of Carlson says.

For instance, you still need to strategically arrange copy in your email designs for these recipients who may not be able to see your images at first. Most importantly, she says, the importance of placing copy where all your readers can see it immediately after they open the message -- at the top – cannot be overstated.

-> Strategy #6. Use more right-side and top-of email hotlinks

In analyzing eyetracking heatmaps, MarketingSherpa’s research team has noticed a trend in click patterns: Readers click more on right-side and top-of-creative links. That’s why you should consider adding extra hotlinks at the very top of your email, even above your “please whitelist us” link.

Hotlinks buried within your text, especially in the middle of a paragraph, aren’t noticed as much because of everything else going on in the newsletter. Move those to the edges of your copy. Also, make sure your headline and your “read more” links are clickable.

Cheliapina found that limiting the number of links at the top of newsletters to four or five works best. Here’s how the links looked from left to right in one of their recent enewsletter layouts:

travel the world | pick a product | grow your money | donate to charity

Too many email designers stress putting their brand at the top of the layout, she says. “We use test results to see what the top four or five links are. Then we put them at the top, and we’ve found that it increases clickthroughs. But sometimes, it’s only two links at the top.”

Useful links related to this article

Past Sherpa articles -
New Eyetracking Test Results: Email Campaign Click Patterns Surprise for Designers:
http://www.marketingsherpa.com/article.php?ident=29795

MailerMailer’s “Email Marketing Metrics Report” article:
http://www.marketingsherpa.com/article.php?ident=30169

LiveNation Case Study - How to Fix Your Email Deliverability - 4 Easy Strategies to Lift Deliverability 20.4% & Sales 143%:
http://www.marketingsherpa.com/article.php?ident=30267

New MarketingSherpa Study Data: One Out of Four Consumers Uses Preview Panes; 59% Block Email Images:
http://www.marketingsherpa.com/article.php?ident=29872

Why (and how) You Should Redesign Your Email Templates for Outlook, Hotmail & Yahoo Immediately - Includes Data Charts from original EmailLabs Study:
http://www.marketingsherpa.com/article.php?ident=29662

MyEmma blog post on subject line length:
http://www.myemma.com/blog/2008/05/28/how-long-should-m
-subject-lines-be-anyway/

Write-up of Alchemy Worx's data on subject line length:
http://publications.mediapost.com/index.cfm?fuseaction=
rticles.showArticleHomePage&art_aid=83385

Carlson Marketing Canada:
http://www.carlsoncanada.com/

Karen Gedney Communications:
http://www.karengedney.com