Demonstration of various file types Express supports in terms of icons.

As a rule of thumb express assumes that any attachments will be presented using an anchor and said element must be within a container ( i.e div ) with a class of attachments-container

An appropriate icon will be displayed based on the value in the href which the CSS tries to detect using a regexp focusing on the end of the string, this can be by-passed by adding in a class ( e.g .ppt => .powerpoint )