Introduction The User synchronisation wizard is only applicable to Microsoft Exchange server users (2000 or 5.5). This wizard will automatically start after you have installed Mail essentials. This wizard will connect to your Exchange/Windows NT/2000 user database for 2 reasons: To allow you to configure rules on a per user/group basis. To validate your Mail essentials license. In order to do this, Mail essentials will retrieve/synchronise its user database with the Exchange server. The method which it uses depends on whether you have Exchange 2000 or Exchange 5.5: If using Mail essentials for Microsoft Exchange Server 2000, then user synchronization will happen between Mail essentials and the Administrative Groups contained in the Active Directory of the Domain Controller on which Exchange Server 2000 is installed through the Global Catalog LDAP service. If using Mail essentials for Microsoft Exchange Server 5.x, then Mail essentials will synchronize users from the selected Exchange sites through DAPI. Note: If you want to operate the Sync wizard in front of a firewall, i.e. you have to connect to the Exchange Server via a firewall, you need to open port 389. For more information on this and a description how to set this up on Microsoft ISA server, please contact support.