Image to text ratio in multipart E-Mail

This topic is not as important as it once was, depending on overall reputation of course. The general rule of thumb is 50/50 text to html ratio, please use the graph on the right side of InboxSys as an indicator. SpamAssassin recommends a minimum of 60% text and a maximum of 40% image coverage, with at least 400 characters of text.

Best practices

• Aim for a good balance of text and images in a way that makes sense for your business/customers.
• Use enough text in the body of the message so subscribers get a sense of the message content whether images are on or off. Many email clients have images turned off by default, so an image heavy email with little text may not get a good subscriber response.
• Use descriptive alternative text (alt text) with images to help subscribers get a sense of the message content with images off.
• Favour a heavier use of images for E-Mails targeted to mobile, since they make great tap targets.
• Send a test E-mail to the InboxSys seedlist before deploying to your subscribers to get data on spam filter performance.
• Test different image-to-text ratios to determine what works best for your business.

Further reading

• This is a good article on the topic.