MessageBody with html not plain text

You would have to physically modify the ascx control on the page to do that. The control can be found here: /CMSModules/Friends/Controls/Friends_Request.ascx Be careful though as if you modify this it will be overwritten when you perform an upgrade/hotfix. I'd suggest starting at the base Friend list page and find out what pages would need to be created (custom) so you could still upgrade your solution.

Thanks for your answer. I already customized this page. I always create a cloned version and customize it in my own folder. Therefore I don't have issues with upgrades.

The question in particular is, if it is actually possible to use html in messages? I already changed the code, that it uses the html version of the friends request template, but it always renderes as plain text in messages. I can't find where I can set it to html encoded.