ASP.net Message board with automatic mass email/notifications

This project is for a private message board that a group of users (100+ users) can post new job listings, and will automatically notify all users (or certain user groups) of the new post. If it is easier/cheaper to use an open source message board to further customize, we would prefer that. We have looked at YAF ([login to view URL]) for example and it works fine on our server, but does not have the functionalities listed below. Message board requirements: - Must be able to allow admin to maintain a catalog of users with contact information (address, phone, company, email, etc.) - Must be able to allow admin to maintain a catalog of companies with information (address, phone, owner, contact person, email, etc.) - Must have user groups (category example: agency, marketing, or both) that will be mass email/notified when there is a new post under their group category. Current server requirements: - ASP.net version 2.0 (2.0.50727) - MS SQL Server 2005