Infinite Loop of Nested Folders

A few weeks ago one user moved a subfolder of her Inbox into another subfolder beneath that one, which triggered the creation of an “infinite” loop of nested subfolders:

I tried to recreate this behaviour but every time I would get the following error (as one would expect):

So I am still not sure how all this happened... Anyway, time to delete those folders! And this is where it got interesting... First thing I tried was obviously to give myself FullAccess permissions to the mailbox and delete the folders myself. However, Outlook returned the following error:

4,000?! Humm... Let’s see how many items are in these folders and how many folders in total. To do this, I used the following two cmdlets (most output removed for simplicity):

[PS] C:\> Get-MailboxFolderStatistics “user” | ? {$_.FolderPath -eq "/Inbox/Pictures of Y"}

Name                              : Pictures of Y

FolderPath                        : /Inbox/Pictures of Y

FolderType                        : User Created

ItemsInFolder                     : 0

DeletedItemsInFolder              : 0

FolderSize                        : 0 B (0 bytes)

ItemsInFolderAndSubfolders        : 0

DeletedItemsInFolderAndSubfolders : 0

FolderAndSubfolderSize            : 0 B (0 bytes)

[PS] C:\> (Get-MailboxFolderStatistics “user”).Count

2922

Ok, so excluding all the default folders and the ones manually created by the user, there’s “only” around 2,890 folders with nothing on them. So why the error about the 4,000 limit?! Time to troubleshoot and get rid of these annoying folders!

Attempt 1

Although I had FullAccess permissions to the mailbox, decided to use ExFolders to grant myself Owner permissions on the top folder and all the subfolders. After almost 1h of propagating the permissions throughout all folders, still got the same error when trying to delete them using Outlook...

Noticed that after trying to delete the folders in Outlook, I would get the following error in the Application log of the Mailbox server (using my account to access the user’s mailbox):

Mapi session "a7198e9f-265f-4e94-b63d-7ee3d78c00c3: /o=domain/ou=exchange administrative group (fydibohf23spdlt)/cn=recipients/cn=motan" exceeded the maximum of 500 objects of type "objtFolder".

Attempt 2

Tried to delete the folders using OWA but a similar result...

Attempt 3

Tried exporting the mailbox to a PST file but it wouldn’t export it because of the folders... The export reaches 100%, then it goes down to 5%, then up again, until it eventually fails.

Tried excluding the top folder from the export using the following cmdlet:

New-MailboxExportRequest "user" -FilePath “\\server\F$\PSTs\user.pst” -ExcludeFolders “#Inbox#/Pictures of Y”

But it still didn’t work. I am not sure if the ExcludeFolders parameter also excludes subfolders or not... Both failed with the following message:

Error: MapiExceptionPartialCompletion: Unable to copy to target. (hr=0x40680, ec=0)

Operation: ISourceFolder.CopyTo

OperationSide: Source

Primary (c0e7ee8d-6f43-430a-b11f-dfba42501ee6)

PropTags: [ContainerContents; FolderAssociatedContents; ContainerHierarchy; DisplayName; RulesTable; 1071710466]

Attempt 4

Tried deleting the folders with MFCMapi but got the following error:

Attempt 5

Tried using Microsoft Exchange Server Information Store Viewer (MDBVU32) but it didn’t work as well. I wasn’t getting any errors and could create and delete other folders, but not the ones I wanted to...

MDBVU32 works “a bit” like MFCMapi. You basically logon and open the Message Store you want to access and then look for the folder (or e-mail) you want to work on.

You then change the operation to DeleteFolder() and click on Call Function... Select the flags you want and then click OK.

In my case nothing would happen for these folders although it would work for any other folders/e-mails...

Attempt 6

Thought about creating another mailbox and simply copy everything across but this would have an impact on the user and the categories wouldn’t be moved, so out of the question for now...

Attempt 7

Changing the type of the folder using MFCMapi:

• Start MFCMapi with Outlook not set to cached mode;
•  Logon and display store table;
• Open mailbox/Top of Information Store;
•  For an email sub folder that you want to delete;
• Change PR_CONTAINER_CLASS to IPF.IMAP from IPF.Note;
• Click OK in the property pane.

 But still the same error when deleting both from MFCMapi and Outlook...

Attempt 8

Isinteg was out of the question as it would take days to run on the DB where the user is and would affect everyone on that DB. So tried moving the mailbox to another DB but it didn’t work... After more than 3h always in 5%, it finally failed with the error (some output removed for simplicity):

Alias                            : user

Status                           : Failed

StatusDetail                     : FailedMAPI

BadItemLimit                     : 5000

BadItemsEncountered              : 0

OverallDuration                  : 04:38:45

TotalFailedDuration              : 03:25:37

TotalQueuedDuration              : 00:00:03

TotalInProgressDuration          : 01:13:04

TotalTransientFailureDuration    : 00:31:19

TotalMailboxSize                 : 1.23 GB (1,320,399,499 bytes)

TotalMailboxItemCount            : 25749

BytesTransferred                 : 0 B (0 bytes)

ItemsTransferred                 : 0

PercentComplete                  : 5

FailureCode                      : -2147024882

FailureType                      : MapiExceptionNotEnoughMemory

FailureSide                      : Source

Message                          : Error: MapiExceptionNotEnoughMemory: Unable to synchronize manifest. (hr=0x8007000e,

                                    ec=1008)

                                   Diagnostic context:

                                       Lid: 55847   EMSMDBPOOL.EcPoolSessionDoRpc called [length=142]

                                       Lid: 43559   EMSMDBPOOL.EcPoolSessionDoRpc returned [ec=0x0][length=739][latency

                                   =46]

                                       Lid: 23226   --- ROP Parse Start ---

                                       Lid: 27962   ROP: ropOpenFolder [2]

                                       Lid: 27962   ROP: ropIncrCfg [112]

                                       Lid: 27962   ROP: ropUpldStStrmBegin [117]

                                       Lid: 27962   ROP: ropUpldStStrmEnd [119]

                                       Lid: 27962   ROP: ropUpldStStrmBegin [117]

                                       Lid: 27962   ROP: ropUpldStStrmEnd [119]

                                       Lid: 27962   ROP: ropUpldStStrmBegin [117]

                                       Lid: 27962   ROP: ropUpldStStrmEnd [119]

                                       Lid: 27962   ROP: ropUpldStStrmBegin [117]

                                       Lid: 27962   ROP: ropUpldStStrmEnd [119]

                                       Lid: 27962   ROP: ropFXSrcGetBufferEx [156]

                                       Lid: 17082   ROP Error: 0x3F0

                                       Lid: 23137

                                       Lid: 21921   StoreEc: 0x3F0

                                       Lid: 27962   ROP: ropExtendedError [250]

                                       Lid: 1494    ---- Remote Context Beg ----

                                       Lid: 1238    Remote Context Overflow

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 7155    StoreEc: 0x3F0

                                       Lid: 6131    StoreEc: 0x3F0

                                       Lid: 22184

                                       Lid: 24312   StoreEc: 0x3F0

                                       Lid: 22360

                                       Lid: 2238    StoreEc: 0x3F0

                                       Lid: 20888

                                       Lid: 24504   StoreEc: 0x3F0

                                       Lid: 24148   StoreEc: 0x3F0

                                       Lid: 23796

                                       Lid: 2478    StoreEc: 0x3F0

                                       Lid: 1750    ---- Remote Context End ----

                                       Lid: 26849

                                       Lid: 21817   ROP Failure: 0x3F0

                                       Lid: 32758

                                       Lid: 16586   StoreEc: 0x3F0

                                       Lid: 22518

                                       Lid: 28874   StoreEc: 0x3F0

                                       Lid: 29516

                                       Lid: 31820   StoreEc: 0x3F0

FailureTimestamp                 : 02/02/2012 10:27:38

FailureContext                   : --------

                                   Operation: ISourceMailbox.EnumerateHierarchyChanges

                                   OperationSide: Source

                                   Primary (c0e7ee8d-6f43-430a-b11f-dfba42501ee6)

                                   Catchup: True

Attempt 9

Already getting desperate, decided to temporarily increase the maximum number of objects that can be handled by Outlook clients by setting both objtfolder and objtfolderview to a value greater than 500 (KB842022 or Maximum open folder objects per logon has been changed).

WARNING: this affects everyone on the mailbox server you set this and it also needs an IS restart so be very careful!!!

As I have a few servers that only host passive DBs, decided to implement the change in one of those servers (I set the registry key value to 3000) and switched over only that DB to that server.

Tried deleting the folders but was getting the same error regarding the 4,000 limit! Not sure why this time... Increased the registry key’s value to 6000 and decided to try again. However, although there were no errors at all on the server, no one could access any mailbox in that server!... Ups! Time to quickly rollback!

Another failed attempt...

Resolution

So how did I fix this problem? Since the beginning that I was thinking about what would happen if I tried to delete the last folder? Because I didn’t feel like expanding almost 3,000 folders (probably for Outlook to complain about the 500 limit!) this had to be done using a script.

Although I love writing scripts, I was avoiding doing this for some reason. But since everything else was failing, I decided to give it a go. And the result was that it worked without any problems!   :-D

I just wanted to quickly try this, so didn’t pay much attention to performance. For this reason, the script is not very efficient because:

it goes through all the folders one by one and then deletes the last one;

starts all over again, goes through all the folders one by one and then deletes the last one;

starts all over again....

In this case it took between 30 to 60 minutes to delete 2,890 folders but it eventually got there!   :)


WARNING: as with every script, make sure you test it properly before running it for a live user!!!


You can also find the script in the Microsoft TechNet Script Repository: Delete Outlook Folders Bottom-Up

# Script: DeleteFoldersBackwards.ps1
# Purpose: This scripts deletes every folder and subfolders for a specific top-folder starting from the last one
# Author: Nuno Mota
# Date:  Feb 2012

[String] $mbxName = "motan@parliament.uk"
[Int] $intCount = 0

[String] $dllPath = "E:\Program Files\Microsoft\Exchange\Web Services\1.1\Microsoft.Exchange.WebServices.dll"
[Void] [Reflection.Assembly]::LoadFile($dllPath)

$Service = New-Object Microsoft.Exchange.WebServices.Data.ExchangeService([Microsoft.Exchange.WebServices.Data.ExchangeVersion]::Exchange2010_SP1)
$Service.AutodiscoverUrl($mbxName, {$True})

# This is the root folder from where we want to start searching for the folder we want to delete.
# Once we find it, then we will go recursively down that folder.
# Other option would be to get the FolderID and start the search straight from there
$RootFolderID = new-object Microsoft.Exchange.WebServices.Data.FolderId([Microsoft.Exchange.WebServices.Data.WellKnownFolderName]::Inbox, $mbxName)
#$RootFolderID = new-object Microsoft.Exchange.WebServices.Data.FolderId([Microsoft.Exchange.WebServices.Data.WellKnownFolderName]::Root, $mbxName)
$RootFolder = [Microsoft.Exchange.WebServices.Data.Folder]::Bind($Service, $RootFolderID)

$FolderView = New-Object Microsoft.Exchange.WebServices.Data.FolderView(1000)
$FolderView.Traversal = [Microsoft.Exchange.WebServices.Data.FolderTraversal]::Deep
$Response = $RootFolder.FindFolders($FolderView)

# Go through all folders under the Inbox folder looking for the folder we want to delete
ForEach ($folder in $Response.Folders)
{
 # Check if the current folder is the folder we want to delete
 If ($folder.DisplayName -eq "Pictures of Y")
 {
  # Found the folder, so start a new Deep search across all its sub-folders
  $FolderView = New-Object Microsoft.Exchange.WebServices.Data.FolderView(3000)
  $FolderView.Traversal = [Microsoft.Exchange.WebServices.Data.FolderTraversal]::Deep
  $Response = $folder.FindFolders($FolderView)
  $RootFolder = $folder
  
  # Loop to go through all sub-folders while there are any
  While ($($Response.Folders).Count -gt 0)
  {
   # Get the last folder so we can then delete it (not very efficient...)
   ForEach ($folder in $Response.Folders)
   {
    #$folder.DisplayName
    $lastFolder = $folder
   }

   Write-Host "Deleting", $lastFolder.DisplayName
   $lastFolder.Delete([Microsoft.Exchange.WebServices.Data.DeleteMode]::HardDelete)
   $intCount++
   Write-Progress -Activity "Deleting Folders" -Status "Folders Deleted: $intCount"

   $Response = $RootFolder.FindFolders($FolderView)
  }

  # Delete the top folder and exit the first ForEach
  #Write-Host "Deleting Top ""$($RootFolder.DisplayName)"""
  $RootFolder.Delete([Microsoft.Exchange.WebServices.Data.DeleteMode]::HardDelete)
  Break
 }
}