Accessing the NON_IPM_Subtree folders in Exchange Web Services

One important and potentially frustrating point for anybody who wants to set permissions on the calendar folder in a mailbox with any Exchange API that allows you to modify the folder DACL’s is that you also need add the same ACE your adding (or modifying) to the FreeBusy Data folder which is one the NON_IPM_Subtree Root folders in a mailbox explained in this KB. Exchange Web Services is no exception to this rule and accessing the NON_IPM_Subtree folders isn’t as straight forward as normal mailbox folders but here’s a method for accessing the freebusy folder and modifying the DACL.

The highest level you can get to easily with EWS is the DistinguishedFolderIdNameType.msgfolderroot which in the basically the Root of the IPM_Subtree if you get the parentfolderID of this folder using a GetFolder Operation this will represent the Root of the NON_IPM_Subtree you can then use this ID in FindFolder operation to discover all the NON_IPM_Subtree folder in this case I’ve used a restriction to find the Free Busy folder based on the folderName. Then once you have the FolderID of the Free Busy folder you can Get and Set the ACL via the normal GetFolder and Update Folder operations.

Okay enough said I’ve put a download of the code here the code itself looks like

PermissionSetType fbPermissionSet = new PermissionSetType();
BaseFolderIdType[] bfBaseFolderArray = new BaseFolderIdType[1];
DistinguishedFolderIdType dfRootFolderID = new DistinguishedFolderIdType();
if (intebExchangeServiceBinding.ExchangeImpersonation == null)
{
EmailAddressType mbMailbox = new EmailAddressType();
mbMailbox.EmailAddress = emEmailAddress;
dfRootFolderID.Mailbox = mbMailbox;
}
dfRootFolderID.Id = DistinguishedFolderIdNameType.msgfolderroot;
bfBaseFolderArray[0] = dfRootFolderID;
ListrfRootFolder = GetFolder(bfBaseFolderArray);
BaseFolderIdType[] bfIdArray = new BaseFolderIdType[1];
bfIdArray[0] = rfRootFolder[0].ParentFolderId;
List fbFolder = FindFolder(bfIdArray, "Freebusy Data");
FolderResponseShapeType frFolderRShape = new FolderResponseShapeType();
frFolderRShape.BaseShape = DefaultShapeNamesType.AllProperties;
GetFolderType gfRequest = new GetFolderType();
gfRequest.FolderIds = new BaseFolderIdType[1] { fbFolder[0].FolderId };
intFreeBusyFolderID = fbFolder[0].FolderId;
gfRequest.FolderShape = frFolderRShape;
GetFolderResponseType gfGetFolderResponse = intebExchangeServiceBinding.GetFolder(gfRequest);
FolderType cfCurrentFolder = null;


if (gfGetFolderResponse.ResponseMessages.Items[0].ResponseClass == ResponseClassType.Success)
{
cfCurrentFolder = (FolderType)((FolderInfoResponseMessageType)gfGetFolderResponse.ResponseMessages.Items[0]).Folders[0];
fbPermissionSet = cfCurrentFolder.PermissionSet;
}

public List GetFolder(BaseFolderIdType[] biArray)
{
try
{
List rtReturnList = new List();
GetFolderType gfGetfolder = new GetFolderType();
FolderResponseShapeType fsFoldershape = new FolderResponseShapeType();
fsFoldershape.BaseShape = DefaultShapeNamesType.AllProperties;
DistinguishedFolderIdType rfRootFolder = new DistinguishedFolderIdType();
gfGetfolder.FolderIds = biArray;
gfGetfolder.FolderShape = fsFoldershape;
GetFolderResponseType fldResponse = intebExchangeServiceBinding.GetFolder(gfGetfolder);
ArrayOfResponseMessagesType aormt = fldResponse.ResponseMessages;
ResponseMessageType[] rmta = aormt.Items;
foreach (ResponseMessageType rmt in rmta)
{
if (rmt.ResponseClass == ResponseClassType.Success)
{
FolderInfoResponseMessageType firmt;
firmt = (rmt as FolderInfoResponseMessageType);
BaseFolderType[] rfFolders = firmt.Folders;
rtReturnList.Add(rfFolders[0]);
}
else
{
//Deal with Error
}

}
return rtReturnList;
}
catch (Exception exException)
{
Console.WriteLine(exException.ToString());
throw new GetFolderException("Get Folder Exception");
}

}
public List FindFolder(BaseFolderIdType[] biArray, String fnFolderName)
{
try
{
List rtReturnList = new List();
FindFolderType fiFindFolder = new FindFolderType();
fiFindFolder.Traversal = FolderQueryTraversalType.Shallow;
FolderResponseShapeType rsResponseShape = new FolderResponseShapeType();
rsResponseShape.BaseShape = DefaultShapeNamesType.AllProperties;
fiFindFolder.FolderShape = rsResponseShape;
fiFindFolder.ParentFolderIds = biArray;
RestrictionType ffRestriction = new RestrictionType();
IsEqualToType ieToType = new IsEqualToType();
PathToUnindexedFieldType fnFolderNameField = new PathToUnindexedFieldType();
fnFolderNameField.FieldURI = UnindexedFieldURIType.folderDisplayName;

FieldURIOrConstantType ciConstantType = new FieldURIOrConstantType();
ConstantValueType cvConstantValueType = new ConstantValueType();
cvConstantValueType.Value = fnFolderName;
ciConstantType.Item = cvConstantValueType;
ieToType.Item = fnFolderNameField;
ieToType.FieldURIOrConstant = ciConstantType;
ffRestriction.Item = ieToType;
fiFindFolder.Restriction = ffRestriction;

FindFolderResponseType findFolderResponse = intebExchangeServiceBinding.FindFolder(fiFindFolder);
ResponseMessageType[] rmta = findFolderResponse.ResponseMessages.Items;
foreach (ResponseMessageType rmt in rmta)
{
if (((FindFolderResponseMessageType)rmt).ResponseClass == ResponseClassType.Success)
{
FindFolderResponseMessageType ffResponse = (FindFolderResponseMessageType)rmt;
if (ffResponse.RootFolder.TotalItemsInView > 0)
{
foreach (BaseFolderType suSubFolder in ffResponse.RootFolder.Folders)
{
rtReturnList.Add(suSubFolder);
}

}
else
{
throw new FindFolderException("Find Folder Exception No Folder");
}
}
else
{
throw new FindFolderException("Find Folder Exception Seach Error");
}

}

return rtReturnList;
}
catch (Exception exException)
{
Console.WriteLine(exException.ToString());
throw new FindFolderException("Get Folder Exception");
}
}