Wednesday, August 23, 2017

Reporting on the Public Folder favorites in a Mailbox using EWS and Powershell

Outlook and OWA allow you to create "Favorites" shortcuts to Public folders (and other folders for that matter) to make accessing them a faster experience.


For those of us keeping pace with grinding Public Folders into dust (personally no longer a fan) and replacing them with Groups, it maybe useful to report on which Public Folders people have Favorited in their mailboxes for a metric and impact point of view. This information should then come in useful if your planing on migrating them (or just for a laugh). Because Public folder hierarchies are relatively complex having the path to the Public folder rather then just the name is generally a lot more useful. So in the script in this blog post we will look at producing a report of the Public Folder favorites and the Path of the Public Folders those shortcuts refer to eg it will produce a report something like the following for each mailbox you where to run it against.



Like other mailbox shortcuts these favorites are FAI (Folder associated items) stored in the Common Views Folder in the Non IPM Subtree folder of a Mailbox. Other names for these items are wunderbar or navigation shortcuts and are documented in https://msdn.microsoft.com/en-us/library/ee157359(v=exchg.80).aspx

EWS allows relatively easy access to FAI items in a Mailbox folder by using an Associated Item traversal in the FindItems operation. eg

$ivItemView.Traversal = [Microsoft.Exchange.WebServices.Data.ItemTraversal]::Associated
 To restrict the query to just returning those items that are public folder shortcuts you need to put a restriction on the  PidTagWlinkFlags property.

The actual properties on the FAI Items must be accessed using extended properties in EWS which are documented in the Exchange protocol document linked above. To work out the path to folder you need to get the PidTagWlinkEntryId property which returns the EntryId of the PublicFolder that the shortcut points to which you then need to convert to an EWSId to access the Public Folder in question. However it is not quite as straight forward as this because the EntryId that is returned by this property isn't convertible with EWS ConvertId operation because of one of the flag properties used. So some transposition of the EntryId is required, because the EntryId format is documented here https://msdn.microsoft.com/en-us/library/ee217297(v=exchg.80).aspx transposing out the incompatible flags so the EntryId can then be used in EWS's convertId operation isn't that hard. eg


$TransposedId = "000000001A447390AA6611CD9BC800AA002FC45A0300" + $Id.Substring(44)
(1A.44.73.90.AA.66.11.CD.9B.C8.00.AA.00.2F.C4.5A. is the provider Id for Public folder and 0300 is folderType for PublicFolder)

Once you have the EWSId of the Public Folder you can then access the PR_Folder_Path property of the folder which should return the full path (with Unicode separators) to the Public Folder in question which you can then add to a report. From a permissions perspective this script needs to be able to access the CommonViews folder in a Mailbox and the Public Folder that the shortcut refers to which maybe a complex thing in some circumstances. As an alternative to binding to the Public Folder using EWS to get the Public folder Path in question you could also use Remote Powershell (Get-PublicFolder) as a alternative if permissions cause an issue.

I've put a copy of this script on Git hub https://github.com/gscales/Powershell-Scripts/blob/master/GetPfShortCuts.ps1

To run this script use Get-PublicFolderShortCuts -MailboxName gscales@datarumble.com

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