Here at Simpleview, we care about our clients and want you to be able to use your email marketing platform to its fullest potential. We understand the frustration that comes with the ever-changing requirements of email clients around incorporating images and graphics into emails. After all, it’s not the most pleasant feeling to fret over the details of your design and ensure that every word and image is perfect only to find it still isn’t rendering properly at the end. 

Due to this frustration, this short blog and checklist outlines current email best practices for getting your images to render properly across a variety of email clients. We hope that having this information at your fingertips ensures that at the end of crafting your email all you’ll need to do is hit send, backed by the confidence that you’ve taken all the correct steps to ensure your images render flawlessly across all devices and email clients.

The Basics

First, let’s go over a few basics for email images:


  • For maximum quality, it’s recommended that you set your images to a resolution of 72 DPI or increase the dimensions of the image. This will resolve blurriness issues and keep your images looking sharp.
  • Images should be RGB color values and not CMYK. This is because CMYK color values won’t work online as they’re only meant for print.


  • For maximum optimization, header/full-width images are not recommended any larger than 600 px.
  • Note: It’s easier for your email marketing platform to adjust images for different devices and email clients when it’s not having to reduce an overly large image file.


  • A PNG file maintains the highest quality. Due to this, a PNG will also increase the size of your email overall. Keeping the image sizes small and running your images through an application, like Squoosh, will reduce the overall size of the image while keeping the desired quality.

Along with these image basics, also keep in mind that too many images or large image files may cause your message to get caught by spam filters.

When wrapping up your email, ensure that:

  • Images don’t distract from the content of the message.
  • Images aren’t so large that they bog down the load time.
  • Images are balanced with text.
  • Images are high quality and fit with the content of the message.

Image Optimization

Remember that if you wish to add padding, you should account for this when sizing your images. Also, with side-by-side images, if the height and width do not match and one is larger than the other, the system won’t render those images to size the same on it’s own in mobile devices. Keeping your images uniform and sized appropriately in advance will solve for sizing issues that show up when images stack in mobile.

For email templates set to full width, you may use larger image files. However, you will still find that if you don’t stay within the outlined basic practices for sizing images appropriately this will be painstakingly evident when the images don’t render properly.

Checklist for Image Optimization:

(_) Convert Images to PNG and use an app like Squoosh to reduce the file size.

(_) Set your email template width to either 600 px or full width.

For email templates set at 600 px:

(_) Use full/large images set to a maximum width of 600 px.

(_) For two side-by-side section block images, set to a total width of 600 px.

  • Example: Each photo set to a 280 px width with 20 px padding.

(_) For three side-by-side section block images, set to a total width of 600 px.

  • Example: Each photo set to a 180 px width with 20 px padding,

(_) Set images as “fit to block.”

Send with Confidence

To wrap it all up, as long as you’re taking these tips into consideration and utilizing best practices while crafting your email to ensure it isn’t image-heavy, the platform and emails will perform to their highest ability. Put these tips into practice and see the results on your next send!