A client that is learning Mailchimp using my online class asked a question about why I recommend a maximum of 20% text on any image when sending an email marketing campaign. Below is the email exchange.
Why Maximum 20% Text on an Image?
Here is the question I received from my Mailchimp class attendee:
What the logic behind the “no more than 20% of an image should be text” guideline? Because it triggers spam filters? Also, is that 20% per individual image? Or the sum of all the images in an email?
I ask because I have a client who wants to include the custom font she uses on her website via a graphic image since Mailchimp doesn’t offer the custom font. So she’d like a header written in the custom font inserted as a graphic. If the “no more than 20%” is per image, then it seems like the graphic should be part of a photo or other pictorial file.
thanks so much!
Reasons for Avoiding Text Saved on an Image
My response is provided below:
There are really two parts in answering your question:
20% Text on Image
According to a widely used email security application “Image spam represents about one third of all traffic on the Internet”. It is widely known that spammers add words to images in order to try to avoid spammy text words being identified (e.g. the word “Viagra” being saved on an image and not typed in the body of the email). The common understanding is that more than 20% of each image shouldn’t contain text (the same applies for social media advertising). Spam filters are good enough to understand that a logo is usually text on an image and therefore ignore the header section when analysing an image.
- Another consideration is that “most email programs block the automatic image downloads by default, which could cause your recipients to delete your email or even mark it as spam”. Test your email campaign without loading images to see how it looks.
- The ratio of Text/HTML to images is another consideration for spam filters. SpamAssassin, a widely used email spam filter looks at both the HTML to Image ratio and Text to Image ratio. We need therefore to include enough text as opposed to images.
I hope this helps.