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To finish with this damn question of the text/image ratio in the email!

In 2017, already, Laura Atkins (who is for me the papess of the deliverability) said this about the text to image ratio:

I'll be honest, I hate this question.

Laura Atkins, Word to the Wise

We reassure you Laura, you are not the only one!

But this question of the text/image ratio is a bit like the Loch Ness monster, everybody talks about it, nobody has ever really seen it. Or maybe they have... but it was my grandfather's uncle's son. So we're not sure.

Rare image of a text/image ratio that pops its head out of the lake

The question of the text/image ratio (yes, I really want to be in first place on Google quickly with this article so I will quote these words a number of times), is clearly the one I was asked the most times in the deliverability training. And for at least 4 years, I've been filing this point in the "Myths and Legends of Deliverability" chapter.

The text/image ratio is a subject that is covered in a huge majority of articles such as "40 tips and tricks for create the perfect emailing" . This is the kind of article built up by copy/paste by content producers who aren't necessarily specialists in the field. As a result, out-of-date information continues to propagate in blog posts, years after its expiration date.

What is the idea of the text to image ratio and its impact on deliverability?

At first, there was nothing.

Then came email, in 1982... but nobody had internet at home, so nobody cared

And then came the web, in 1991... but nobody had internet at home, so nobody cared

Finally, the internet started to make its mark, people started to create email addresses, Hotmail passed its head. And as always, some smart guys took advantage of it.

Thus was born spam!

Display the source image
Note the wonderful mix of French and Spanish. Succulent.

As a result, the battle was on! The first anti-spam filters were created. One of the most famous ones is undoubtedly SpamAssassin.

At that time, the means are limited. Filters mainly analyze keywords to decide if an email is spam or not.

But tricksters are always clever. They will therefore put the words that can betray them in images.

The anti-spam filters are therefore obliged to react. And that's where the text/image ratio is invented. It is assumed that an email with a lot of images is potentially an attempt by spammers to hide keywords that could give them away!

We could obviously stop here... except that at this stage, we are between 2000 and 2005!

Since then, water has flowed under the doors (yes, sometimes it happens) and anti-spam techniques have had 15 years to perfect. Spam filters have totally revolutionized the way they work. You'll see in the expert opinions below what it's like today.

But at least you understand where this text to image ratio thing comes from and how it relates to spam and deliverability.

My opinion

Yes, yes, I am talking about OPINION! Because in the beautiful world of deliverability, each webmail/FAI has its own anti-spam recipe (even if in some cases they use common technologies) and these recipes are not revealed to the public (otherwise it would be too easy for the spammers).

Today, deliverability is largely based on the concept of reputation. This reputation is an attempt for webmails/FAIs to understand if a campaign sender has good practices. This idea could be summarized in two main points:

  • Has the sender received the consent of the recipient?
  • Are the emails appreciated or rejected by the recipient?

To evaluate these two questions, the different filters use all the signals at their disposal: complaints, bounces, spamtraps, blacklists, opens, clicks, ... These signals vary from one webmail/FAI to another, but the first ones on the list (complaints, bounces, spam traps, blacklists) are used by all.

In this context, the text/image ratio CAN be one of the signals. But it is a signal that has a negligible influence compared to the others. The primary objective in deliverability is to generate engagement and limit the risk of annoyance from the recipient.

So about the content of the email. The priority is interaction with the recipients, the user experience... whatever the proportion of images!

Expert opinion on the text to image ratio

Anna-Sophie Marsh, Director of Deliverability at Epsilon

Anne-sophie is the Director of Epsilon's deliverability department. She was Account Manager at Emailvision and Email Marketing specialist at CeWe Color. Find her on LinkedIn.

The ratio of text to image in itself is no longer a primary criterion for deliverability today.

For most of our B2C customers Gmail / Microsoft / Yahoo represent >60% of the lists. These ISPs have much more complex spam filtering techniques, mostly based on the reputation of the sender:

  • how have their users interacted with emails from this sender over the past ~30 days?
  • Are the routed volumes regular?
  • Does the sender demonstrate good data management (low invalid, inactive and spam trap rates)?

Smaller ISPs sometimes have more basic or outsourced filtering systems that can give more weight to the content of the email. But I don't remember seeing any problem related to the text/image ratio (though I have received comments from ISPs about the fact that a multipart is advertised when only an HTML version is sent... but that's another topic).

In conclusion, I would say that it's not the text to image ratio per se that's the problem - it's more about how recipients will interact with the email. For example, including a large image that takes a long time to load will probably irritate the recipient who might delete the email without reading it; or including too small text in an image that will make the email unreadable on mobile will not encourage the recipient to click... so you have to think about optimizing the creative for mobile to encourage positive interactions.

Sébastien Fischer, Deliverability Consultant at Badsender

Sebastien is the main deliverability consultant at Badsender. He was Deliverability Manager at Cabestan, Deliverability Consultant at Adobe and Deliverability Executive at Email Vision. Find him on LinkedIn.

Personally, I remain of the same opinion as Laura Atkins (Wordtothewise). It's almost 2021 and in my opinion this "20/80", "40/60", "37.289/63.711" ratio is completely outdated.

I have done over 50 audits, over 100 monitoring, over 10 migrations over the last 4 years and at no time have I seen block bounces (or ISP/Webmails returns) that indicated the text to image ratio that caused the block.

And finally, I always receive in my Gmail inbox full image emails from big luxury brands (whose name I will not mention :p)

Pierre-Yves Rodet, Freelance CRM and Data Project Manager

Pierre-Yves is a freelance CRM and Data Project Manager. He has worked as an emailing project manager for Accor, Digital Director Full service for Groupe La Poste and Head of Data Management at Publicis Sapient. Find him on LinkedIn.

This topic is more about UX than deliverability.
Deliverability is based on 3 pillars:

  • technical parameters of the SMTP
  • Good hygiene of the base (inactive cleaning, sending rate)
  • A good system for handling unsubscribes and bounces and above all respect for the law.
  1. In UX we notice that texts are no longer read, we are witnessing an "instagramization", hence the emergence of new skills such as "copywriting". A simple image and a strong call to action are the right recipe for a successful email.
  2. The new support for reading emails is the mobile, so the importance of the "title" tag that is included in the subject line, also "alt" tags if the mobile user is offline.
    The mail must be imperatively responsive with a construction of simple images and visible enough to adapt easily to the small screen.
    "Call to action" and customer benefit processed in text to allow quick reading in any receiving circumstance. A message received but not visible is not a deliverability issue.
  3. Take the time to test your messages before validating your campaigns. The testing part is often the weakest part of the production chain, but it is vital.

Thibault Sarlat, Senior Email Marketing & Deliverability Consultant 

Thibault is Team Leader Delivrability France at Cheetah Digital and was a deliverability consultant at Emarsys. Find him on LinkedIn.

Need help?

Reading content isn't everything. The best way is to talk to us.

I have never seen this parameter be THE reason for a block or a spam classification. It's just a poem that if added to data quality/segmentation issues or more generally reputation issues can tip the balance to the wrong side of the bounce/spam folder.

Some luxury brands have messages that are mostly 85-20 or even 90-10, and it works very well.

This is a (pre)historical factor.

But you have to take this into account as well, because if the images are not loaded when they are opened, there is not much left to encourage them to be loaded or clicked on.

Florent Destors, deliverability consultant at Selligent

Florent is a deliverability consultant at Selligent since 2014. Prior to that, he was at eCRM tools project manager (Selligent, Neolane, Eulerian, ...). Find him on LinkedIn.

As far as I'm concerned, I continue to push the use of text and images, not for filtering reasons (we usually have a text version of the email that is part of the multipart sending) but for usability and user experience and accessibility issues. What happens when images are not loaded by default? That the ALT tags have been filled in any way? We tend to forget about visually impaired people who may receive emails with no "readable" text.

Laurent Depoorter, CEO of Oxemis

Laurent is the CEO and founder of Oxemis which markets Oximailing, an emailing solution. Find him on LinkedIn.

So for my part, I think it's much less impactful than in previous years. We don't remember a case of blocking recently for this reason (though modern editors try to balance this by encouraging users to play with blocks). But the trend is, in my opinion, that it is less impactful.

A concrete example? The rules of SpamAssassin. Extract from the score file (available in the source) in 2013 :

score HTML_IMAGE_RATIO_02 2.199 0.805 1.200 0.437
score HTML_IMAGE_RATIO_04 2.089 0.610 0.607 0.556


score HTML_IMAGE_RATIO_02 0.001
score HTML_IMAGE_RATIO_04 0.001

The scoring went from 2.199 (max) to 0.001 (max). This shows the trend. After all, we are talking about one antispam among thousands and its "default" configuration. But this is in line with my feeling.

Having said that, don't put words in my mouth, I'd still recommend keeping a certain balance. If only so that content-based filters know what the message is about (and an "alt" on a global image isn't going to help).

Sebastiaan de Vos, founder of Inboxsys

Sebastiaan is the founder of the deliverability monitoring suite Inboxsys. Before that, he was Head of Deliverability at Emarsys for 6 years. Find him on LinkedIn.

Original opinion in English:

The ratio itself is not what's most relevant. Of course, there are still spamfilters heavy weighing the relation between text vs. HTML, but their number is declining. The ratio also depends much on the doctype used. Pure HTML5 does not require inline CSS, which is likely to reduce the HTML ratio significantly.

French translation :

The ratio itself is not what is most relevant. Of course, there are still spam filters that compare the weight of text and HTML, but their number is decreasing. The ratio also depends a lot on the doctype used. Pure HTML5 does not require inline CSS, which is likely to reduce the HTML ratio considerably.

Gabriel Gastaud, Director of Professional Services at Validity

Gabriel was Director of Professional Services at Validity, but also an emailing trainer at Visiplus, a professor of email marketing at IMMD in Lille and a deliverability specialist at Experian Cheetahmail. Find him on LinkedIn.

The Image/Text ratio is primarily a way to raise awareness that images should be matched with text and to avoid "full image" emails.

There is no perfect ratio in my opinion for the simple reason that nobody knows how to formulate a clear calculation on this notion. From a technical point of view, it is possible to evaluate the weight of HTML content compared to images, or to evaluate the share of text in the HTML code, but in both cases, we will not analyze exactly this famous "image/text ratio" as it is presented to advertisers.

For my part, I would say that this idea of ratio has the merit of easily making people understand one of the basics of emailing to avoid seeing the newsletters of the 90s, but is no longer really interesting from a deliverability perspective.

It remains much more relevant to focus on the respect of these few basic good practices:

  • Avoid images with a width of "100%", "800px" or even 600px...
  • Make sure there is text and not just images
  • Ensure unified hosting of images, on the brand's own domain
  • Make sure to fill in the "Alt" tags

Hopefully this helps a little 😉

Pierre Galiegue, Deliverability Manager at Sarbacane

Pierre is currently Deliverability Manager at Sarbacane. Before that, he was Senior Deliverability Manager at MailXpertise, Deliverability Consultant and Executive Producer at EmailVision. Find him on LinkedIn.

As others have said before me, the 40/60 ratio (or others) is no longer relevant in the sense that the text/image ratio does not have the same weight for spam filters as it once did.

Indeed, this ratio was initially valuable, because many years ago, spam filters brought a great value to the content of messages, it was the time of mass e-mails (spam) sent with only a clickable image as content.

Nowadays and with the advent of behavioral analysis indicators have evolved: Reputation of the IP / Domain pair, User behavior (opening / clicking / complaining / deleting / deleting without opening ... ), List hygiene, HTML content (W3C), Compliance with SMTP standards and authentication (Concurrences / Cadences / SPF / DKIM ... ) etc. ...

Thus, this ratio text / image does not have the same weight as before and that's why we can see messages containing only images arrive in the main box.

The only case, where this could be relevant, would be for rare messaging services that would base their analysis on content filters (hello BtoB!) and here again it remains debatable.

However, as others have pointed out, it is important to keep a mix of text and images in your communications for obvious reasons of accessibility (images not displayed by default, loading of images, maximum weight allowed, handicap situation . ) but this is a subject that has already been presented in the past!

We also want your opinion on the text to image ratio!

We started this discussion on LinkedIn to compile expert opinions on the subject! Please feel free to bring the discussion alive directly on LinkedIn or send us your feedback via our contact page. We will regularly update the expert opinions in this article!

And if you want deliverability advice, don't hesitate to contact us!

Photo by David Preston on Unsplash

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