On 5.0a now, but had the same issue with 4.2e. My AD users can login, and new accounts auto create as necessary, but they have to manually edit their profile and put in their own e-mail address. My alfresco-global.properties does include a "ldap.synchronization.userEmailAttributeName=mail" entry line. That's the only thing that seems to be related to e-mail that I can see. What am I missing?