When writing the email use Insert-Image instead of Attach. I would be sure to resize the image to a reasonable size with an image editor before inserting it.

If you insert an image into the body, it will still be 'attached', even though it won't be listed as an attachment in the usual way. Another option is to upload the photo to your personal storage space such as OneDrive or Google Drive, and then email the link to the image. The image can then be displayed in a web browser. If you don't have a storage space, there are plenty of free image-hosting services.