Don’t Trust Outlook

People who know me well won’t be surprised by my mistrust of Outlook. I regularly rag on Outlook for supporting and encouraging poor time and e-mail management practices. This column, however, isn’t about that and it isn’t just about Outlook.

How e-mail marketing messages are displayed is a messy, complex business. There’s no one software client or browser that has an overwhelming majority of users; what works on one system doesn’t necessarily work on another. Unfortunately, I regularly come across testers who hold the misconception that if something looks right in their version of Microsoft Outlook, then it’s OK. I’m not entirely certain of the reason for this. I suspect it’s a few factors: the belief that Internet Explorer and Microsoft Office are ubiquitous and, therefore, practically everyone must use Outlook, plus the human tendency to instinctively trust the evidence before one’s own eyes.

Outlook can seriously let you down as a testing tool. It’s too forgiving and too helpful, with features beneficial for office workers. If people send you badly formatted content, it may still be displayed correctly. However, if you’re testing an e-mail marketing message, this can be a significant problem.

The kinds of issues that occur include:

  • Decoding header. We have a client who has been sending out messages with malformed subject lines for months. In Outlook, they look properly formatted. In some other clients, they look like this:

    The issue hasn’t been corrected because the client doesn’t see the problem and considers it a low priority. The above subject line is in Japanese, but I recently received a marketing e-mail with the same issue in English.

  • Ignoring headers. Outlook often ignores or overrides e-mail content headers (often called MIME headers). Thus if you send out a message that claims to be text but contains HTML, Outlook may render the HTML while other e-mail programs will display the HTML code itself.
  • Ignoring character sets. Sending a message claiming to be one character set but actually containing another can result in correct display in Outlook but complete gobbledygook in other programs.
  • Forgiving rendering. Badly coded HTML may display fine in Outlook (depending on the version) but have any number of issues in other clients, including the troublesome black text on a black background problem that occurs all too frequently.

The solution to this problem is twofold. First, ensure that your e-mail creation and delivery environment has good quality controls, including checking headers and validating content.

Second, never completely trust a single e-mail client. Test widely. Even if you run a client that’s extremely unforgiving, there may be commonly used systems that possess particular bugs and cause rendering problems even with correctly formatted messages.

For a business-to-consumer (B2C) environment, that probably means signing up for a variety of free Web mail services as well as checking the popular desktop clients, such as Outlook, Outlook Express, Thunderbird, and Apple Mail. For business-to-business (B2B), the issue is trickier. Systems such as Lotus Notes and various versions of Outlook become more common, and so more of an issue. Most reputation service providers and deliverability companies provide rendering tools that can show you how your messages will look in a variety of clients, thus alleviating the problem.

Remember, rendering issues can be far more than just misaligned graphics. They can cause messages to be completely illegible, resulting in irritated recipients and failed campaigns. Take the time to make sure your messages render for your audience, and don’t just trust what you see on your desktop.

Until next time,


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