Remove duplicate Outlook items from a folder

Question

issue

1. Outlook 2016 corrupted while I was moving items from an online archive into a pst file.
2. The PST file has been recovered .... but many

Answer 1

Dears, thank you VERY MUCH you saved my day :-) I have simplified the duplicate search as in my case I imported muliple duplicates from PST files but the full mail body didn't matched, I don't know exactly why, as I am sure those mail are true duplicates So my simplification is to match ONLY the receive TIME STAMP and the SUBJECT I also add an error exception I got some times on the function: Set olDuplicatesFolder = olFolder.Folders("Duplicates") And did different format for the debug.print messages So here's my code, that works very well for me. THANK YOU

Attribute VB_Name = "DelDupEmails_DATE_SUBJECT"
Sub DeleteDuplicateEmails_DATE_SUBJECT()
Dim allMails As Outlook.Items
Dim objMail As Object, objDic As Object, objLastMail As Object
Dim olFolder As Folder, olDuplicatesFolder As Folder
Dim strCheck As String
Dim received As Date, lastReceived As Date

Set objDic = CreateObject("scripting.dictionary")
With Outlook.Application.GetNamespace("MAPI")
    Set olFolder = .PickFolder
End With
If olFolder Is Nothing Then Exit Sub

On Error Resume Next
Set olDuplicatesFolder = olFolder.Folders("Duplicates")
On Error GoTo 0
If olDuplicatesFolder Is Nothing Then Set olDuplicatesFolder = olFolder.Folders.Add("Duplicates")

Debug.Print "Sorting " & olFolder.Name & " by ReceivedTime..."
Set allMails = olFolder.Items
allMails.Sort "[ReceivedTime]", True
Dim totalCount As Long, index As Long
totalCount = allMails.Count
Debug.Print totalCount & " Items to Process..."
'MsgBox totalCount & " Items to Process..."

lastReceived = "1/1/1987"
For index = totalCount - 1 To 1 Step -1
    Set objMail = allMails(index)
    On Error Resume Next
    received = objMail.ReceivedTime
    On Error GoTo 0
    If received < lastReceived Then
        Debug.Print "Error: Expected emails to be in order of date recieved. Previous mail was " & lastReceived _
            & " current is " & received
        Exit Sub
    ElseIf received = lastReceived Then
        ' Might be a duplicate track mail contents until this recieved time changes.
        ' Add the last mail to the dictionary if it hasn't been tracked yet
        If Not objLastMail Is Nothing Then
            Debug.Print olFolder & " : Found multiple emails recieved at " & lastReceived & ", checking for duplicates..."
            'MsgBox "Found multiple emails recieved at " & lastReceived & ", checking for duplicates..."
            objDic.Add GetMailKey(objLastMail), True
        End If
        ' Now check the current mail item to see if it's a duplicate
        strCheck = GetMailKey(objMail)
        If objDic.Exists(strCheck) Then
            Debug.Print "#" & index & " - Duplicate: " & lastReceived & " " & objMail.Subject
            'Debug.Print "Found Duplicate: """ & objMail.Subject & " on " & lastReceived
            'MsgBox "Found Duplicate: """ & objMail.Subject & " on " & lastReceived
            objMail.Move olDuplicatesFolder
            DoEvents
        Else
            objDic.Add strCheck, True
        End If
        ' No need to track the last mail, since we have it in the dictionary
        Set objLastMail = Nothing
    Else
        ' This can't be a duplicate, it has a different date, reset our dictionary
        objDic.RemoveAll
        lastReceived = received
        ' Keep track of this mail in case we end up needing to build a dictionary
        Set objLastMail = objMail
    End If

    ' Progress update
    If index Mod 100 = 0 Then
        Debug.Print index & " Remaining... from " & olFolder
        'MsgBox index & " Remaining..."
    End If
    DoEvents
Next
Debug.Print "Finished moving Duplicate Emails"
MsgBox "Finished moving Duplicate Emails"

End Sub

Function GetMailKey(ByRef objMail As Object) As String
  On Error GoTo NoHTML
  'GetMailKey = objMail.Subject & objMail.HTMLBody
  GetMailKey = objMail.Subject ' & objMail.HTMLBody
  Exit Function
BodyKey:
  On Error GoTo 0
  'GetMailKey = objMail.Subject & objMail.Body
  GetMailKey = objMail.Subject ' & objMail.Body
  Exit Function
NoHTML:
  Err.Clear
  Resume BodyKey
End Function