Email HTML - what's possible, what's not

The key difference between a standard HTML web page and an email using HTML is that they are catering for two very different program platforms. A web page for example has one sole requirement - to be viewed through a web browser such as Microsoft's Internet Explorer, Mozilla's Firefox or Apple's Safari. Emails are intended to be read via an email client.

This could be software-based such as Microsoft Outlook or Outlook Express, Apple Mail or Eudora. Naturally there is very little similarity between the two - they are designed for separate tasks.

The one element which they both can share is that they are able to read and display HTML4.0. This is the first public version of what we know as web pages, and as you may be able to guess from that statement, is quite old. Where advancements have been made in HTML and other technologies to provide a richer and more fulfilling experience on the web, email has stayed put.

This is primarily down to the type of information that can be carried in a generic web page and reducing those elements to uphold secure environments within mail exchanges.

Although there is a general consensus that mail exchange programs and email as a whole are happy to take the HTML4.0 format, there are no global agreements between vendors as to what specific elements can or cannot be used, as each have their own opinions on what is best for their users.

There are however some hard and fast rules which you can apply in the design and coding of your email marketing messages to ensure they are how they were intended when they reach their destination.

Spit and polish

When creating websites, many labour saving devices can help reduce repetition of certain things such as font sizes, colours and types. This is done using external style sheets (CSS) to easily and efficiently manage the look and feel of entire sites.

Unfortunately this method makes a request to an external programming file, which is seen as a breach of security or unsafe for the recipient. As a result this request will be stripped from your email's HTML file when received by a mail exchange.

All the elements on your HTML email must use what is known as in-line styles. This means applying specific style attributes to each tag on your page, something that can become time consuming.

For example: <font style="font-size: 12px; color: red; font-family: arial;">hello world</font>

Hold it together

Another favourite of modern web developers is using <div> containers to create blocks of content that can be manipulated and styled with CSS. Using techniques such as floating, scaleable liquid multi-column layouts can be created.

Sadly this technique is a recent development and was not part of the original HTML4.0 Schema, meaning that it is not possible to accurately use these styles in email marketing.

Instead you will have to use tables to ensure your message elements stay in the intentional layout format and avoid the use of padding in your style for content as this varies between browsers.

In closing

Certain elements and their attributes are refused outright by certain email clients.

Remember that security issues and the fight against spam are always going to take precedent over how pretty our bulk email marketing campaigns look and we should appreciate the reasoning behind these restrictions. It is still possible to create visually stunning, effective emails regardless of what may be seen by some as limitations.