Email is one of a website's most powerful tools for strengthening customer service and increasing user confidence and trust in both the site and the company. Confirmation messages and transactional email can complete the user experience. They do this by reaching out to customers in ways that are otherwise impossible for websites, which must sit and await the user's approach.

For email to fulfill its potential, however, messages must be designed for optimal usability.  They must have a user interface that both works in a crowded inbox and accounts for most people's typically hectic approach to reading mail.

Unfortunately, most companies don't seem to view email creation as a user interface design activity, possibly because messages are often text-only, and thus don't seem "designy."

Judging by many of the messages we tested, email design often seems to be a side effect of the software implementation and consists of copy written by the programmer late at night. Alternatively (and even worse), some messages are hard-hitting, written by aggressive sales people without a true understanding of Internet marketing's emphasis on relationship building.

In our latest research, we asked users to rate a wide range of transactional email on 6 criteria. Sure enough, "design" was the quality that received the lowest ratings.

User Research: Two Studies

We tested 92 transactional email messages for usability, observing users as they interacted with email in the inbox view and read individual messages. We conducted this research in two rounds, with 5 years between the two studies, allowing us to assess trends in users' email-related behavior.

In both studies, most of the messages were order and service confirmations or shipment notifications , but we also tested reservation confirmations and e-tickets; available-now notices; billing and payment notices; cancellations, returns, refunds, rebates, and bonuses; information request responses; government responses; customer service messages; failure notices; and registration and account information.

Study 2 included all of these message types, as well as newer uses of transactional email, such as social networking updates, information posting notifications, meeting confirmations, and recommendations from friends (sent through the now-common website feature that lets users "tell a friend" about a product or article). As the many message types show, transactional email offers abundant opportunities for enhancing a site's relationship with its customers.

A striking conclusion from the studies is that processing email is stressful. Users frequently told us that they were too busy to deal with certain email messages, and that they considered any fluff in messages a waste of time. When they check their email, users are typically dealing with multiple requests for their time — whether from their boss, colleagues, or family. People just want to be done with most email, and quickly move past anything that is not absolutely essential.

It has long been a strong usability guideline to be brief when writing for the Web; email writers must be even briefer.

Surviving Spam-Filled Inboxes

Transactional email has three goals:

  1. Avoid being mistaken for spam. Email must survive users' ruthless pruning of inbox messages.
  2. Be a customer service ambassador. Email should enhance a company's reputation for customer service and increase users' confidence in their dealings with the company.
  3. Prevent customers from calling in. Telephone call centers are expensive. However, rather than simply eliminating contact information (which undermines the previous goal), ensure that your email answers all common questions in easily understandable terms.

All three goals are important, but if an email message fails the first goal, it also automatically fails the other two simply because people won't read it.

In addition to the legitimate messages listed in the previous section, we also tested spam messages (unsolicited promotions) and phishing messages (fraudulent email that purports to come from a legitimate sender). The good news is that users rarely fall for spam. In Study 2, participants opened only 12% of spam messages. However, users' harsh attitudes toward spam and their summary actions to dismiss it have negative implications for legitimate mail. For example, 80% of users wouldn't open a legitimate message from the Walgreens pharmacy because of its vague subject line.

To avoid having messages summarily deleted from the inbox, email designers are restricted to working with two design elements in the form of microcontent: the From and Subject fields. To maximize impact, designers must optimize both.

In most cases, the From field should show a recognizable brand name (if available). When possible, the field should also include a function that clearly distinguishes the message as a transaction rather than an advertisement. In Study 2, "JetBlue Reservations" and "BestBuy Online Store" were the most effective sender names. Both names were 20 characters long, which is appropriate because many inbox views truncate From fields after 20 or 25 characters. If you have a longer name, you might have to rely on the first 20–25 characters to convince users that you're legitimate.

People simply don't open messages that don't have recognizable sender information. In both rounds of research, this was the number one reason users gave for not opening email.

We saw many subject lines that worked and many that didn't. The main differentiator was the degree to which the subject line explicitly related to a customer-initiated transaction. Participants deleted email with subject lines that seemed too much like spam (such as "Important information").

"TiVo Rewards Program Ends May 28" was one of the highest-performing subject lines from Study 2. Contrast its specificity, recognizability, and call to action with "Confirmation of Account Activity," which was a vague subject line (what activity?) that didn't earn clicks.

The very best subject line in Study 1 was "Order has shipped," and similar subject lines continued to score very well in Study 2. In fact, "Order has shipped" was so good that many users didn't open the message. This is fine if your message contains no additional information that requires the user's immediate attention. Typically, our participants said they'd save these messages and open them only if the package didn't arrive and they needed the tracking number.

A good subject line is gold. Invest accordingly in writing the copy.

Avoid or Minimize Message Sequences

Companies that scattered a transaction across too many messages caused several usability problems. Users had difficulty keeping track of the messages, which contributed to inbox overload. This in turn increased the odds that users would overlook a message or think that they'd already read it.

For transactions that involve the shipment of physical products, it's usually best to send two messages:

  1. A transaction confirmation immediately after the user completes the online order process. If such a message doesn't arrive within a few minutes, users often suspect that something went wrong.
  2. A shipping confirmation with the tracking number once the package has been sent.

In our studies, some companies sent a third message with an order summary. This confused users.

Tell Users What They Want to Know

We asked users to make a prioritized list of the content they wanted to see inside email messages. The lists were different for each message type, but the general guideline is simple: start with the information that matters most to users in the transaction context. In particular, almost everyone looked for tracking numbers, even if they never tracked packages. A tracking number seems to serve as comforting evidence that there's an actual package and that it's on its way.

Not surprisingly, the most requested information was a simple description of exactly what was ordered (or what activity was completed). Users requested this 58% more frequently than the second most popular information.

Lower on the priority lists, but still important for most transactions, was information about what to do if things go wrong.

In general, you should write a message according to the users' priorities, starting with the information they're typically looking for. Email that begins with marketing messages or other seemingly irrelevant information runs a major risk of being deleted, because people might never scroll down to see the information they need.

Transactional Email Builds Trust

Good email that respects users' time and quickly tells them what they need to know can do wonders for your customer service reputation. People don't really trust websites, but when they get a confirmation message, it seems like something is actually happening.

At the same time, poorly designed email can erode a company's credibility. We asked users to rate their level of trust in each sender on a 1–7 scale; poor design elements decreased a company's ratings by up to 2 points. Lack of contact information was another primary concern, as was a company sending too much email, but even things like not getting to the point quickly could hurt trust. Remember, users are extremely busy and stressed when reading email. Wasting their time makes them feel like you don't care. Worse, you become part of the problem, not the solution.

Trends in Transactional Email Usability

Because our first user research with transactional email was conducted 5 years ago, we can compare those findings with our current study's findings to assess trends in email usability.

The first, and most important, observation is that all of our usability findings from the original study continue to hold . The basics remain the same. The report's first edition contained 74 design guidelines, and they're still true — though we had to tweak a few in the light of recent developments. The new edition has 143 guidelines; there are about twice as many things to consider now because users have become more skeptical and more rushed when processing their email. But the new considerations are in addition to the old issues; they don't replace them.

One change is that it's important to use a descriptive sender name in addition to a good From email address. This is due to changing email software. Some Web-based services display only the user ID from email addresses, which is rarely helpful without a domain name. For example, in Gmail, a message from British Airways was shown as coming from "British," which was obviously insufficient to entice users to open it. Supplementing the user ID with a full sender name solves the problem and is now a stronger guideline than in the past.

Messages from Third-Party Users

For Study 2, we tested a new type of message: those initiated by third parties — as opposed to the user or the website — including recommendations from friends and social network notifications.

These two message types prompted opposite reactions in the study: users welcomed recommendations from their friends, but were negative toward social network notifications.

Websites often let people send an email message through their site to a friend or colleague — they might, for example, forward an article or inform a friend about a recommended (or wished-for) product. Participants valued receiving these messages mostly because they were a personal recommendation from a friend or trusted party. To strengthen this effect, it's important that such messages feature the friend's name prominently in the sender information and that the friend be able to customize the email with a personal message.

Conversely, users were annoyed by messages sent by various social networking services that they either didn't know or didn't want to join. A request to join, say, Facebook, LinkedIn, or MySpace was substantially more intrusive than a recommendation to look at an article or a product listing. Thus, in the former case, the requirements are substantially higher for (a) truly convincing the recipient that the message was indeed initiated by a friend and (b) concisely explaining to the recipient why they would benefit from taking action on this unsolicited invitation.

Unchanged: Message Usability

One thing didn't change during the 5 years between Study 1 and Study 2: the appallingly low usability of most transactional email.

In most of our research with websites, we find decent usability progress when we repeat a study after several years. For example, in a recent study of store finders and locators, users' ability to find location information on websites had increased to 96% from the 63% success rate we recorded for the same task 7 years before.

In contrast to the improving website picture, transactional messages continue to exhibit the same amount of usability problems as we saw 5 years ago: vague subject lines continue to dominate, and the body text of many messages continues to be too long, too difficult to scan, and too lacking in clear facts important to users.

Website usability exists in a favorable environment, as users increasingly understand the predominant design conventions and continue to get better connectivity and larger screens. In contrast, email lives in an ever-more hostile environment — that is, in an ever-more crowded inbox. Users in our research were overwhelmed by their inboxes and increasingly felt pressured by unsolicited or fraudulent email.

Users' ratings of trust in the messages decreased slightly from Study 1 to Study 2, even though the actual messages were no worse in the second study.

Given the deteriorating context surrounding transactional email, it's not good news that message design is staying constant. Transactional email holds great promise for strengthening the bond between users and websites, but this potential will be realized only if sites allocate sufficient resources to their email user experience.

Bypassing Search Engines as Gatekeepers

As search engines solidify their web dominance and charge ever-larger fees for SERP ads, it's becoming a strategic imperative for websites to bypass the search engines and establish direct relationships with users. Transactional messages are one of the best ways to do this because they build connections through a different channel — that of electronic mail.

Email is one of the Internet's oldest uses and that's an advantage: It's unmediated by search engines or other third parties and it's 1:1 by nature. Both of these features are inherently supportive of customer relations.

As it turns out, another use of email is also a great strategy for bypassing search engines to drive traffic to your website: the email newsletter. While there are many similarities between these two email forms, the newsletter is an inherently different media form because it's published repeatedly and focuses on content instead of transactions. Thus, the detailed design guidelines for email newsletters are different than those discussed here.

Beyond their immediate branding effect, transactional messages can also drive traffic to your site long after you send them. Some users maintain a "clean mailbox" policy and erase messages as quickly as possible. However, when people do save transactional messages, those messages become a pointer to your site that can reemerge exactly when users are primed to do business with you again. These saved messages become searchable within a user's email program and thus once more bypass external search engines.

In a common scenario, users might search their email records for the name of a product or a product type that they want to purchase again. Users will be very likely to pull up your old messages if they follow the guidelines for a recognizable From field, clearly stated subject lines, and body text that starts with the most important user-oriented information.

These guidelines ensure the usability of a message when it's initially received, but they also do double duty by enhancing the message's findability years later. You might call this effect "deferred SEO," except that the goal is not to trick external search engines into giving you a high rating. The goal is simply to help users recognize your transactional messages the next time they need your product.

Confirmation email and other automated transactional messages are great for connecting a website with its customers and for closing the loop in e-commerce and other transactions. Just remember: Email is a user interface. Design your messages accordingly, aiming for maximum usability.

Full Report

The full research report with actionable design guidelines for email usability is available for download. (Now available in an updated edition, including newer research than the studies summarized in this article.)