HOWTO: Find Distribution List Membership for a Given Recipient

• Microsoft Exchange Server, version 5.5 Service Packs 1, 2
• Microsoft Active Directory Service Interfaces, versions 2.0, 2.5

SUMMARY

You can use the Active Directory Service Interfaces (ADSI) to obtain the distribution list membership for a given Microsoft Exchange Server Recipient object. This article describes how to accomplish this using either Microsoft Visual C++ or Microsoft Visual Basic.

NOTE: This is an alternative to using the members collection returned by the IADsUser::Groups method. One key difference is that enumerating the members collection will give you the group objects rather than the group names. See the documentation for IADsUser::Groups for more information.

MORE INFORMATION

An Exchange Server Recipient object holds its distribution list(s) membership through the LDAP memberOf attribute. This attribute is either returned as a single string or a variant array of strings.

The following code will bind to a Recipient object using LDAP, cache the membership attribute, and print the distribution list(s) to the screen.

Using Visual C++

/*
   include activeds.h
   link with activeds.lib and adsiid.lib
*/ 

HRESULT func ()
{
   HRESULT hr;
   IADs *pADs;
   VARIANT pvProp;
   BSTR bstrpropName;
   long lLBound, lUBound;
      
   // Initialization
   VariantInit(&pvProp);
   CoInitialize(NULL);
   bstrpropName = SysAllocString(L"memberOf");
      
   // Bind to an Exchange recipient object
   hr = ADsGetObject(L"LDAP://servername/o=org/ou=site/cn=recipients/cn=fhc", IID_IADs, (void**) &pADs );
   if ( !SUCCEEDED(hr) )
   {
      return hr;
   }
      
   // Get recipient's members
   hr = pADs->Get(bstrpropName, &pvProp);
   if (FAILED(hr))
   {
      return hr;
   }
   
   if (VT_BSTR == pvProp.vt)  /* only one DL */ 
   {
      printf ("%S\n", pvProp.bstrVal);
   }
   else                 /* multiple DLs in an array */ 
   {
      SafeArrayGetLBound(pvProp.parray, 1, &lLBound);
      SafeArrayGetUBound(pvProp.parray, 1, &lUBound);
      
      for (long i = lLBound; i <= lUBound; i++)
      {
         VARIANT svar;
         SafeArrayGetElement(pvProp.parray, &i, &svar);
         if (VT_BSTR == svar.vt && svar.bstrVal)
            printf("\n%S",svar.bstrVal);
      }
   }
   
   // Releasing
   VariantClear(&pvProp);
   SysFreeString (bstrpropName);
   pADs->Release();
   
   return S_OK;
} 

Using Visual Basic

Dim RecipObj As IADs
Dim memberOf As Variant

Set RecipObj = GetObject("LDAP://servername/o=org/ou=site/cn=recipients/cn=fhc")
memberOf = RecipObj.Get("memberOf")

If IsArray(memberOf) Then 'User is on more than one DL
    For Each member In memberOf
       Debug.Print member
    Next
Else
    Debug.Print memberOf
End If 

REFERENCES

For more information about Active Directory Services Interfaces (ADSI), please refer to the following Web site:

http://www.microsoft.com/adsi/

Additional query words: kbXchge kbXchge550 kbMsg kbADSI kbGrpMsg

Keywords : kbADSI kbXchge kbXchge550 kbMsg kbfaq kbGrpMsg kbDSupport
Version : winnt:2.0,2.5,5.5
Platform : winnt
Issue type : kbhowto