It may depend on your config. Here's a solution relying on Mime Mail and Mail System, as Mime Mail integrates smoothly with Rules.
Download and enable these 2 modules. Then you'll have a few steps configuring it :
- Mail System: select MimeMailSystem in both "Site-wide default MailSystemInterface class" and "Mime Mail module class" drop-down list.
- Mime Mail: change it from "Plain text" to "Filter HTML".
Now when you edit your rule, you'll see an action "Send HTML mail to all users of a role". Select editor role. You're done :)
Find even more details in this step by step tutorial: How to Send HTML Emails in D7 using Rules
EDIT : Alternative solution.
- Download simplenews and enable both simplenews and simplenews rules. Set up the module.
- Create a editors newsletter. Deactivate Subscription block
- Enable "Use as simplenews newsletter" in the content type options you wish to send as HTML formatted email.
- Create a rule : after editing a user account, condition user has role editor, subscribe user to newsletter editors (and reverse rule to unsubscribe)
- Create a rule : after saving a node, condition content-type is..., send newsletter :The newsletter node to be sent.: [node]