Emails can be sent from the control panel of your site in a rich text/html format instead of just plain text.
1. From the control panel under 'Utilities' choose 'Send Email'
2. The 'Mail Message' field will show a WYSIWYG editor to add rich text to your email messages.
*Note* If the WYSIWYG is not appearing, it may be necessary to turn the WYSIWYG editor on for your whole site. This can be completed through 'Custom Settings' --> 'Turn WYSIWYG editor On' --> Choose 'Yes'