We have a version of SendMailFunction (and SendMailToUserFunction) in CMS, Web and ODF-Web.

In CMS, there is no notion of site, but in Web and ODF-Web, there is as site. We recently added the SiteGetter component to manage URL dynamically, it can manage web contents, ODF contents and contents which are not these ones.

I think it would be a good idea to use it in these functions (for web plugins).