Once an image is deleted from the image gallery, the image in the email will no longer display. This is because images in emails need to be hosted to be accessible online and if you delete the image, there will no longer be a source. There is a small chance that the image is cached by the ISP, computer, or browser and the image can be displayed in the email after it is deleted.
If you are deleting images to save space, we recommend purchasing the Image Hosting Plus. This will increase your image storage space to Unlimited.