Toward the end of the '90s, a debate raged over whether it was best to use HTML or plain text in email marketing. People debated sniffing technologies, the limitations of AOL's rich text format, and the lift and brand awareness from HTML as opposed to plain text.
In time, the issue resolved itself. More email systems became HTML capable, and people got used to receiving HTML messages. AOL started supporting proper HTML. The only remaining question was whether to continue sending multipart or HTML-only messages.
Just as the dust had settled, some systems capable of displaying HTML stopped loading images under certain circumstances.
Increased focus on security and privacy has led many common email clients to block HTML image loading. This now affects many of the biggest providers and the most popular software, including AOL, Hotmail, Yahoo, Gmail, Outlook 2003, and Thunderbird. Though HTML isn't always blocked or prevented from displaying, it can greatly affect how your message appears.
Worse, these systems don't work exactly the same. Most leave a blank space where an image would be. In Yahoo, the space is gray; Gmail displays a broken image icon. Some, such as Gmail and Thunderbird, will also display alternate text if it's provided. Others don't. AOL not only blocks image loading but also disables hypertext links.
Despite all this variability, you can optimize your recipients viewing experience.
Examine Your Message Without Images
First, optimize how your message appears with no images. Image blocking puts more emphasis on the message text, including the headers. Look closely at your message. Remember, you only have a few seconds to capture people's interest. Ask yourself:
If you've been using images as headlines, it may be time to return to text. Most email clients can handle rudimentary style sheet information to improve presentation. Ensure the sender address clearly identifies your organization and brand. The subject line should clearly identify the content. Though ambiguous subject lines may intrigue recipients, they may also cause recipients to ignore the message. Finally, as mentioned in a previous column, make sure all CAN-SPAM compliance copy is text, not images.
Some clients will display alternate text you can specify in your HTML coding. Appropriate alt tags can use the blank image space and encourage recipients to turn on image downloading.
Get Added to the Address Book
Second, become a known sender. A known sender, typically defined as being in the recipient's address book, is increasingly more important. AOL and Yahoo can filter messages by known senders; challenge-response systems, such as EarthLink, block delivery of email from unknown senders; and most image-blocking systems typically only block images from unknown senders.
Use of a consistent sender address, then, is vitally important. It starts at list signup. Tell subscribers what the list-sending address will be when they sign up or subscribe. Encourage them to add the address to their address books. Send the confirmation email from this list address. Remind subscribers that adding your list address to their address books may cause your email to be filtered or not properly displayed.
Text at the top of your message can remind recipients to add your address to their address books if images aren't loading. Most systems offer buttons that enable image loading or add the sender to the address book.
Consider providing a link for users who can't see the message properly, such as "If you can't see this email, please click here." Although this doesn't get your message displayed properly in their system, it does ensure anyone can view the message, regardless of email client or security settings.
If you haven't evaluated your email messages without images, it's high time you did. Your open and click-through rates may depend on it.
Until next time.
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Derek Harding is the CEO and founder of Innovyx Inc., a member of the Omnicom Group and the first e-mail service provider to be wholly owned by a full-service marketing agency. A British expatriate living in Seattle, WA, Derek is a technologist by background who has been working in online marketing on both sides of the Atlantic for the last 10 years.