For readers who are blind or have low-vision, use alt text (which is read by screen readers) to describe images.
Add alt text to an image in an email
Right-click the image, select Format Shape, select Layout & Properties , and then select Alt text.
Or select the image, select Format > Format Shape, select Layout & Properties , and then select Alt text.
Add an image title, a detailed description of the image, and why the image is important to your message.
Since assistive technology doesn’t read words within images, if there’s text within your image, include that text in the alt text description.