I am using WordPress 2.6.5
The moment I installed this plugin, Email2Friend, all my post formatting (paragraphing, line breaks) disappeared, and raw HTML for other plugins appeared in the posts. As well, a click on the link it put at the bottom of each post led directly to my admin dashboard.
Needless to say, I deactivated it immediately.
The Email2Friend website does not seem to have a contact link on it.