I created a trigger for the EmailMessage object that, when executed, updates a field on the parent case (runs a SOQL that counts all the emails on the case that are unread and updates the count). The update event on the trigger does not fire when a user opens an unread email from the emails related list on the case even though this action changes the status on the email from New to Read.  Does someone know the reason and is there any way I can trap for this event?

thanks

Brian