@clacke I think you are right, it's the form - or more likely something behind the form that's sanitising the HTML. I haven't noticed this here before, probably because people don't sent in much HTML. Much of it is plain text or a Markdown variant which I process for them.
@clacke I have access and have had a look. It's PHP and I think it's the use of 'stripslashes' on the form contents. Of course, this function strips backslashes! I imagine the goal originally was to de-quote stuff that's on its way to the database, but the form data gets dropped into a file - which I post-process.
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko