It’s been known for a while that emails over 102KB will get clipped in Gmail.

That is one reason to keep your email file sizes down, but what if I told you that you could get a higher open rate by simply reducing the weight of your emails? Isn’t that a much more compelling reason to keep the weight of your emails down?

Our test results:
We found during our Mobile Optimisation case study with Kitbag that lighter weight HTML and images always gave us higher open rates.

We believe the main reason for this is the increasing number of people reading their emails on mobile phones, which often have slower download speeds. People reading emails on their mobiles also have extremely short attention spans so if your email doesn’t download fast enough they won’t hesitate to delete it or move on to the next message.

This is going to be an increasingly important issue for email marketers as mobile usage is growing every month. We recently tracked a number of Lyris clients in the UK and Europe and found 44% of the openers were using a mobile: 

 How can you shed those unwanted Kilobytes?

An email’s weight is determined by the amount of HTML used and the size of the images. So the easiest way to shed that weight is to use the least amount of HTML and the lowest resolution images possible. This is how I reduced the weight of the emails we tested:

• Removed unnecessary breaks

• Ensured all text styles are placed within a table row rather than being repeated multiple times in P tags
• Try not to use image maps – they add many lines of extra code
• Don’t use too much Alt text. Gmail doesn’t even display Alt text if you add too much, so don’t write a novel.
• Comment tags – These are tags inserted by coders to make it easier to edit HTML. In emails they are often used to show where certain parts of the email begin and end, such as “Navigation starts here” or “Footer ends here.” In my opinion they are not necessary and are a good way to cut down the weight of your emails.

By removing the above items I was able to reduce the size of this JOY The Store email from 27KB to 15.2KB.

Any more suggestions out there for putting email on a diet?

About the Author:

Andrew King

Andrew is senior strategy consultant at Lyris. He joined Lyris in 2010 and consults with clients to ensure they are getting the most out of their email marketing programs. Before coming to Lyris, Andrew worked in marketing for several companies including the Institute of Directors and Kia Motors.