These tips are focused on images, but the same points apply to other file types.
The ideal dimensions for your images depend entirely on the size of your pages and emails. Sizing the image width to the exact width of your page or message will make sure it displays at full size without increasing load times or resource use more than necessary.
In the Stationery section of the Composer, check the Message Width setting:
- For an image to stretch fully across the email, your image should be this many pixels wide
- For an image to fit into one column of a two-column section, it should be 50% of your message width
On the Design tab of the editor, click Edit Page Properties to view the width setting:
This setting should determine the maximum width of your images, and you can scale them as needed from there.
Follow these guidelines to make your assets load faster, reduce the frequency of image load issues, keep images from stretching/distorting to fit in a space, and help your image library itself will load faster
- Make sure images are 'optimized for web' – this is usually a setting/option in image editors like Photoshop
- Do not use High Resolution images for emails or landing pages (causes long load times)
- The DPI for your images should be less than 72
Image FILE size
Sizing images appropriately can make for a better user experience, but also better email deliverability for the following reasons:
- Many corporate IT departments have strict limits on email content and total message size
- Email providers can mark emails as spam purely based on size
- Long email load times can detract from open and click rates, particularly on mobile devices
Tips for Success
- Use an image compression tool – many free options are available, and loss of quality is minimal
- Ensure that your email message stay below 100 kilobytes total, including images
- Keep individual images below 20 kilobytes
Naming and storage
Since email providers pay attention to image names, alt text, and other metadata when scanning emails, it's important to consider these factors while managing your files. In addition, organizing your files well can save you significant time and hassle in the long run.
Tips for Success
- Use descriptive file names, including prefixes and suffixes
(eg, "Fr1-First Image: Bastille Day is Coming-SgCEOs" for your first image in a France campaign targeting a segment of company CEOs)
- Aim to organize your files so that a new employee on your team could understand the system on their own
- Give your folders specific names to match their purpose
- Avoid duplicate names are impossible. While there are some method by which computers can compensate for identical file names, none of them are without performance trade-offs.