Outlook VBA Stumbling Over "Undeliverable" Report - vba

Question

I have VBA code that marks selected messages as read, assigns a category and moves them to a subfolder.
Mail Delivery System "Undeliverable" reports are not marked-as-read, categorized or moved.
I tried to duplicate the For Each loop to look for olReportItem. (I realize that it is inefficient to have two loops, but am just doing it this way for testing purposes so I can keep all the beta code in one section.)
Sub TestMoveToSubfolder()
'With selected emails: (1) mark as read, (2) assign category, (3) move to subfolder
On Error Resume Next
Dim thisFolder As Outlook.MAPIFolder
Dim objFolder As Outlook.MAPIFolder
Dim objItem As Outlook.MailItem
Dim objStore As Store
Set thisFolder = Application.ActiveExplorer.CurrentFolder
Set objStore = thisFolder.Store
Set objFolder = thisFolder.Folders("REFERENCE_DESIRED_FOLDER")
'Be sure target folder exists
If objFolder Is Nothing Then
MsgBox "I can't find the designated subfolder.", vbOKOnly + vbExclamation, "INVALID SUBFOLDER"
Exit Sub
End If
'Confirm at least one message is selected
If Application.ActiveExplorer.Selection.Count = 0 Then
Exit Sub
End If
'Loop through emails
For Each objItem In Application.ActiveExplorer.Selection
If objFolder.DefaultItemType = olMailItem Then
If objItem.Class = olMail Then
objItem.UnRead = False
objItem.Categories = "INSERT_DESIRED_CATEGORY"
objItem.Move objFolder
End If
End If
Next
'TEST SECTION to work with undeliverable reports
Dim objItem2 As Outlook.ReportItem
'Loop through nondelivery reports
For Each objItem2 In Application.ActiveExplorer.Selection
If objFolder.DefaultItemType = olMailItem Then
If objItem2.Class = olReportItem Then
objItem2.UnRead = False
objItem2.Categories = "INSERT_DESIRED_CATEGORY"
objItem2.Move objFolder
End If
End If
Next
Set objItem2 = Nothing
Set thisFolder = Nothing
Set objFolder = Nothing
Set objItem = Nothing
Set objStore = Nothing
End Sub

Answer 1

The problem is related to declaring the objItem in the following way:
Dim objItem As Outlook.MailItem
or
Dim objItem2 As Outlook.ReportItem
To be able to iterate over all items selected in Outlook you need to declare the objItem as object in the code.
Typically to find out the exact line of code causing the issue you need to remove the following line:
On Error Resume Next
There also no need to have two separate loops, you may combine two conditions into the single loop:
Dim objItem As Object
'Loop through emails
For Each objItem In Application.ActiveExplorer.Selection
' check for regular mail items
If objItem.Class = olMail Then
objItem.UnRead = False
objItem.Categories = "INSERT_DESIRED_CATEGORY"
objItem.Move objFolder
End If
' check for report items
If objItem.Class = olReportItem Then
objItem.UnRead = False
objItem.Categories = "INSERT_DESIRED_CATEGORY"
objItem.Move objFolder
End If
Next

Answer 2

As I said in my comment, no olReportItem class exists. Declaring objItem As Variant (or As Object) will allow iteration between all selection clases (in a unique iteration. Something like that:
Dim objItem
For Each objItem In appOutlook.ActiveExplorer.Selection
If objFolder.DefaultItemType = olMailItem Then
If objItem.Class = olMail Then
objItem.UnRead = False
objItem.Categories = "INSERT_DESIRED_CATEGORY"
objItem.Move objFolder
ElseIf objItem.Class = olReport Then
Stop
'do whatever you need here...
End If
End If
Next

Answer 3

For the record, the final working code is below. I don't want to mark this as the answer since that seems like I am trying to take credit for the work of #niton, #FaneDuru and #Eugene Astafiev, but thanks to their input the question has been answered and the problem is solved.
Sub TestMoveToSubfolder()
'With selected emails: (1) mark as read, (2) assign category, (3) move to subfolder
Dim thisFolder As Outlook.MAPIFolder
Dim objFolder As Outlook.MAPIFolder
Dim objItem As Object 'could also define as Variant
Dim objStore As Store 'used if you want to find subfolder of current mailbox
'set folder locations
Set thisFolder = Application.ActiveExplorer.CurrentFolder 'alternative is Set thisFolder = objItem.Parent
Set objStore = thisFolder.Store 'alternative is to bypass thisFolder and use Set objStore = objItem.Parent.MAPIFolder.Store
On Error Resume Next
Set objFolder = thisFolder.Folders("REFERENCE_DESIRED_FOLDER")
On Error GoTo 0
'Be sure target folder exists
If objFolder Is Nothing Then
MsgBox "I can't find the designated subfolder.", vbOKOnly + vbExclamation, "INVALID FOLDER"
Exit Sub
End If
'Require that this procedure be called only when a message is selected
If Application.ActiveExplorer.Selection.Count = 0 Then
Exit Sub
End If
'Loop through selected items
For Each objItem In Application.ActiveExplorer.Selection
If objFolder.DefaultItemType = olMailItem Then
If objItem.Class = olMail Then
objItem.UnRead = False
objItem.Categories = "INSERT_DESIRED_CATEGORY"
objItem.Save
If thisFolder <> objFolder Then objItem.Move objFolder
ElseIf objItem.Class = olReport Then
objItem.UnRead = False
objItem.Categories = "INSERT_DESIRED_CATEGORY"
objItem.Save
If thisFolder <> objFolder Then objItem.Move objFolder
End If
End If
Next
'Clean up
Set thisFolder = Nothing
Set objFolder = Nothing
Set objItem = Nothing
Set objStore = Nothing
End Sub