Prepare your email for blocked images
More often than not, your emails will be displayed to recipients without showing images. Here are some tips to make the best of it:

Use image descriptions wisely
Descriptions show up in place of a blocked image. Use the description field of each image to promote a message.

Add captions
Add a compelling caption that drives the point home, even if the image is blocked.

Mind the preview pane
Make sure the top third of your template includes compelling text that addresses the main point of your message.