The use of HTML in email allows us to create engaging and branded messages, but achieving consistency across a variety of desktop and web based clients is a minefield of disappointment. There are sensible reasons for restricting some HTML features within an email message, although the features that different email clients choose to honour vary greatly.

Email distribution firm Campaign Monitor have put together a great article which details the features that are supported by each client. Most notably, corporate favourite Microsoft Outlook 2007 has particularly poor support for many basic HTML and CSS features - most frustratingly it will not display background images either as CSS styles or HTML tag attributes.

Knowing the restrictions of HTML email I was recently able to design an email template for a client which would render consistently across all email clients. I started by designing a standard HTML page with a set of CSS styles and then used the excellent Premailer tool which converts all CSS styles into in-line styles. This is an important task to ensure compatibility, but would be an arduous process to do by hand - what's more Premailer also provides a reminder of compatibility issues that may occur based on the HTML code you provide - Very handy!