Customize email with login and password info

Hello. I’m working on a site, and the client wants to customize the email that is sent out to people who register for the site with HTML, images, etc. I found a plugin (New User Email Setup) that allows me to change the text, but when I try to add an image, it doesn’t work.

I’ve done a lot of searching, and nothing is really helping. Anyone know of a plugin or anything where I can fully customize this email?

Thanks in advance!