Excluding public folders when enumerating Outlook folders

Question

I have an Outlook plugin that searches all Outlook folders for certain information.
However, some users have been complaining that the plugin searches public folders as well, which are huge in certain corporations, and that in turn makes the search very slow.
I now use the following mechanism to search Outlook folders:
NameSpace nameSpace = outlookApp.GetNamespace("MAPI");
Folders accountFolders = nameSpace.Folders;
try
if (nameSpace == null || accountFolders == null)
return null;
for (int i = 1; i <= accountFolders.Count; i++)
MAPIFolder accountFolder = accountFolders.Item(i);
MailItem res = null;
try
res = ScanFolder(accountFolder, mailId, scanUI);
finally
if (accountFolder != null) Marshal.ReleaseComObject(accountFolder);
if (res != null) return res;
return null;
finally
if (accountFolders != null) Marshal.ReleaseComObject(accountFolders);
if (nameSpace != null) Marshal.ReleaseComObject(nameSpace);
I've tried to look at the MAPIFolder object, but I didn't find any flag that could help me distinguish standard folders from public folders. Is there a way to do that?
Thanks,
Jan

Answer 1

Read the PR_MDB_PROVIDER property (DASL name http://schemas.microsoft.com/mapi/proptag/0x34140102) using MAPIFolder.PropertyAccessor.GetProperty, convert it to hex using MAPIFolder.PropertyAccessor.BinaryToString. For the PF store objects,
PR_MDB_PROVIDER property will be pbExchangeProviderPublicGuid (78B2FA70AFF711CD9BC800AA002FC45A) - you can see that property (and others) in
OutlookSpy: click IMAPIFolder button.
Dmitry Streblechenko (MVP)
http://www.dimastr.com/redemption
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