Setting ACL on Exchange Mailbox

Question

I'm trying to add a group to a mailbox (in C#). I'm using a mix of CDOEXM, DirectoryServices.AccountManagement calls, and failing. This is my code:

// userDe is a DirectoryEntry
IExchangeMailbox exMb = (IExchangeMailbox)userDe.NativeObject;
IADsSecurityDescriptor securityDescriptor = (IADsSecurityDescriptor)exMb.MailboxRights;
IADsAccessControlList acl = (IADsAccessControlList)securityDescriptor.DiscretionaryAcl;
AccessControlEntry ace = new AccessControlEntry();

// groupName - I have successfully created the group earlier
ace.Trustee = groupName;
acl.AddAce(ace);
securityDescriptor.DiscretionaryAcl = acl;
exMb.MailboxRights = securityDescriptor;

// How do I save it?
exMb.CommitChanges() etc etc
...or userDe.Properties["ntSecurityDescriptor"] = securityDescriptor;

Not sure what to do next, everything I try results in a compilation error or a InvalidCastException.

Please help

Answer 1

Got it after quite a bit of pain (the integer values I am setting somehow correspond to enum values in the API but I couldn't get them to work). The variable userDe is a DirectoryEntry.

            IExchangeMailbox exMb = (IExchangeMailbox)userDe.NativeObject;
            IADsSecurityDescriptor securityDescriptor = (IADsSecurityDescriptor)exMb.MailboxRights;
            IADsAccessControlList acl = (IADsAccessControlList)securityDescriptor.DiscretionaryAcl;
            AccessControlEntry ace = new AccessControlEntry();
            ace.Trustee = groupName;
            ace.AccessMask = 1;
            ace.AceFlags = 2;
            ace.AceType = 0;

            acl.AddAce(ace);
            securityDescriptor.DiscretionaryAcl = acl;
            IADsUser iadsUser = (IADsUser)userDe.NativeObject;
            iadsUser.Put("msExchMailboxSecurityDescriptor", securityDescriptor);

            iadsUser.SetInfo();