Sven's solution is correct.
This has been fixed in the new version 1.4, as all emails now are in HTML and thereby also fix the problem with /r/n some users had (dependent on there host).
Also the plugin has been tested to work on Joomla 3.0 and CB 1.9.
Also there are added new features!
Read more about it in the official forum thread:
www.joomlapolis.com/forum/13-general-plugins/169035-official-cb-public-mail-thread
