Hi.  I would think it could be done but it is unlikely to be something that would be supported so it would be your decision.  You just have to be careful to set all fields properly on the form used for mail rules including any hidden fields.  The most simple way you could do it is to send each user a button with the code to create the mail rule when they click it.  You could also use an agent I suppose but you would have to code some way of getting each user's mail file location.  You could get this information using code in the agent to search in the Domino Directory.