Image file size: less than 1 MB, preferably under 200 kB.
File type: png, jpg or gif
Image width: 516 pixels
Image file size
Large files make emails slower to show up. Make sure your images are less than 1 MB in size, and preferably under 200 kB.
Most images that you’ll want to include in your email newsletter already come in one of these formats. JPG is for photos, GIF is for illustrations, and PNG is for anything.
Most Mira email templates will scale an image to a width of 516 pixels. If you want extra pixel density on displays that support it, you can double the width of you image. However, this might cause problems for users of Outlook.
How do I get my image to the right width and size?
Use any image processing software. The most popular commercial program is probably Adobe Photoshop. But to just resize an image, Paint included with Windows works just fine. There are also many free online services, but your mileage will vary.