[@robkk Moderator 11 years, 6 months ago]

the bbPress Notifications plugin author has html emails on their to-do list.

1.1.0
Add option to notify on new topics & replies on selected forums only
Support for HTML tags in emails – https://www.dfactory.eu/support/topic/html-in-emails/
Stop plugin settings being removed on deactivation
1.0.0
Initial release

https://www.dfactory.eu/plugins/bbpress-notifications/