Pre-header text, also known as snippet text, is the HTML text that appears before the header of an email. It often appears in very small font and does not clash with the main body of your email message.

Some common types of pre-header text include:

• View HTML version
• Whitelisting instructions
• View on mobile phone or device
• Forward to a friend
• Message that elaborates on the subject line, summarizes the main CTA or offer

There are 3 main reasons why it’s important to incorporate pre-header text into your email campaigns.

The first is that most of the major email clients default to blocking images. Therefore consumers look at your email in some type of preview pane and decide whether or not to download your images based on the HTML text they can see. Well-crafted pre-header text can encourage your consumers to open your email, which is the first step of engagement.

The second reason is that everyday more and more people are viewing their email messages on some type of mobile device. Mobile phones are largely image-unfriendly, and when there is no pre-header text, the consumer often has to scroll through quite a bit of HTML code to get to the main message. Pre-header text essentially helps turn your email into mobile-friendly messages.

Third reason - For users of Outlook 2007, Gmail, and the iPhone – all very widely adapted tools, these applications automatically pull the pre-header text into the inbox. This additional text in the inbox provides information to the consumer about what your message contains, and influences their decision whether or not to open your email.

Pre-header text is valuable email real estate. Here are a few tips on how to best use this real estate:

• Keep it to one or two lines, be short and to the point. Combine multiple elements on a single line when possible. Don’t waste space by including blank lines.
• Craft your pre-header text with the goal of getting your subscribers to open your email and read more. Rather than using it to message a forward to a friend or include whitelisting instructions, incorporate those types of elements into your header.
• Know that alt text can be read as snippet text. Even if you use a one-by-one pixel as the first element in your email, include a meaningful message and it will appear as pre-header text in Outlook and Gmail.