The network administrator needs to check the permissions -- both Client Permissions and those on the Security tab -- in Active Directory. They may be set too loosely.

--
Sue Mosher, Outlook MVP
Author of Configuring Microsoft Outlook 2003
http://www.turtleflock.com/olconfig/index.htm
and Microsoft Outlook Programming - Jumpstart for
Administrators, Power Users, and Developers
http://www.outlookcode.com/jumpstart.aspx

"Armin" wrote in message ...
We do have a problem that all user can eachother modify the calendar rights.
All useres are common domain members and no changes (rights) are donne on the
exchange server.
Clients are using Outlook2003. Server is SBS2003.
Has anyone an idea? Thank you.