Blackbaud Sphere allows users to send emails to the constituents in their Sphere database. The emails are customizable allowing users to add images as content along with text. This solution outlines any possible size limitations for images that are uploaded as email content.
There is no set limit for image size when uploading images to your Email Content. However, the smaller the image, the better the resolution. If users experience problems uploading an image, it is best to try sizing it down a bit in order to better fit the content editor.