server: add ability to add/remove labels

server/src/lib.rs

@@ -83,6 +83,8 @@ pub fn sanitize_html(html: &str) -> Result<String, SanitizeError> {
         }
     };
     // Default's don't allow style, but we want to preserve that.
+    // TODO: remove 'class' if rendering mails moves to a two phase process where abstract message
+    // types are collected, santized, and then grouped together as one big HTML doc
     let attributes = hashset![
         "align", "bgcolor", "class", "color", "height", "lang", "title", "width", "style",
     ];