[Zope] I would like to add a password property to the acl_users list

Hello, I am building a site that allows users to be members of projects. Members get extra access to the site. I also want the members to receive e-mail notifications when certain things change on the site. It seems like a better idea to add the e-mail address to the acl list rather than build a mirror list of users to deal with membership and e-mail notification. Is there a way to do this? Thanks for your help. Paul Friedlander Danfoss paulfriedlander@danfoss.com