vba - How to uniquely identify an Outlook email as MailItem.EntryID changes when email is moved

Question

My company uses a single email address for customers to send requests and orders to. we created an Access database that import emails into a table. The table creates it's own unique identifier for each email imported but is not supposed to import an email twice. The system was working as we were only concerned with emails coming into the inbox and didn't need anything more than that.

However we now need to know the "flow", "traffic" and "workload" of the email pool that this account is. The email that comes into the inbox is categorized and then moved to a folder called "my_tasks" and a subfolder the folder named as 1 of the four CSRs to be worked on by a manager. This email is then dealt with and the CSR moves it to a subfolder under another folder called "Completed".

So email comes into Inbox, gets moved to my_tasksjoeblow is dealt with and gets moved to CompletedCanada.

Currently I have code that iterates through the folders and finds each email, grabs the fields we want to store and then inserts them into the table. All of this is done in Access through VBA code.

Private Sub ImportEmailItem(objMailItem As Outlook.MailItem)
On Error GoTo ImportEmailItem_Error

    ' Set up DAO objects
    Dim rstMB As DAO.Recordset
    Dim dskippedFolderMailCount As Double
    Dim strSQLrMB As String

    strSQLrMB = "SELECT * FROM tblMailBox WHERE OLID='" & objMailItem.EntryID & "'"

    Set rstMB = CurrentDb.OpenRecordset(strSQLrMB)

        With rstMB
            If Not .BOF And Not .EOF Then

                .MoveLast
                .MoveFirst
                While (Not .EOF)
                    If .Updatable Then
                        .Edit
                            rstMB!Subject = objMailItem.Subject
                            rstMB!Body = objMailItem.Body

                            Call subCategory(objMailItem)

                            rstMB!CSR = IIf(Len(objMailItem.Categories) = 0, "Unassigned", objMailItem.Categories)
                            rstMB!Importance = objMailItem.Importance
                            rstMB!Region = objMailItem.Parent
                            rstMB!DateModified = objMailItem.LastModificationTime
                            rstMB!FlagCompleted = objMailItem.FlagRequest
                            rstMB!folder = objMailItem.Parent
                            rstMB!Path = objMailItem
                        .Update
                    End If
                .MoveNext
                Wend
            Else
                rstMB.AddNew
                    rstMB!olid = objMailItem.EntryID
                    rstMB!ConversationIndex = objMailItem.ConversationIndex
                    rstMB!ConversationID = objMailItem.ConversationID
                    rstMB!Conversation = objMailItem.ConversationTopic
                    rstMB!To = Left(objMailItem.To, 250)
                    rstMB!CC = Left(objMailItem.CC, 250)
                    rstMB!Subject = objMailItem.Subject
                    rstMB!Body = objMailItem.Body

                    Call subCategory(objMailItem)

                    rstMB!CSR = IIf(Len(objMailItem.Categories) = 0, "Unassigned", objMailItem.Categories)
                    rstMB!Importance = objMailItem.Importance
                    rstMB!From = objMailItem.SenderEmailAddress
                    rstMB!Region = objMailItem.Parent
                    rstMB!DateReceived = objMailItem.ReceivedTime
                    rstMB!DateSent = objMailItem.SentOn
                    rstMB!DateCreated = objMailItem.CreationTime
                    rstMB!DateModified = objMailItem.LastModificationTime
                    rstMB!FlagCompleted = objMailItem.FlagRequest
                    rstMB!folder = objMailItem.Parent
                rstMB.Update
            End If
            .Close
        End With

ImportEmailItem_Exit:
    Set rstMB = Nothing
    Exit Sub

ImportEmailItem_Error:
    Debug.Print Err.Number & " " & Err.Description

    Select Case Err.Number
        Case 91
            Resume Next
        Case 3022
            Resume Next
        Case -2147221233
            MsgBox "Customer Care Account Name is incorrect, please enter the Mail box name as seen in your outlook client.", vbOKOnly, "Mail Folder Name Error"
            Me.txtMailAccountName.SetFocus
            Exit Sub
        Case Else
            MsgBox "Error #: " & Err.Number & "  " & Err.Description '& Chr(13) + Chr(10) & IIf(mail.Subject Is Null, "", mail.Subject) & " " & IIf(mail.ReceivedTime Is Null, "", mail.ReceivedTime)
'            DoCmd.RunSQL "INSERT INTO tblImportReport(ImportDate,ImportFolder,ImportResult,ImportEmailCount) VALUES (#" & Now() & "#,'" & mailFolder & "', 'Error " & Err.Number & "', " & dMailCount & ")"
            Resume Next 'cmdImportEmail_Exit
    End Select

End Sub

Is there a way to uniquely identify an email with a single field no matter whether it has been moved or not?

I have an idea of what I could do to make sure I have the right email and get the original entry in my database. If there was no other way I could concatenate fields together to form a unique field and then get the database table's primary key field value.

Answer 1

You can use the PR_SEARCH_KEY property (DASL name http://schemas.microsoft.com/mapi/proptag/0x300B0102) - it does not change when a message is moved. It can be accessed through MailItem.PropertyAccessor.GetProperty, but unfortunately you cannot use PT_BINARY properties in Items.Find/Restrict.

You can also set your own named property using MailItem.UserProperties.

UPDATE:

For PR_SEARCH_KEY, see https://msdn.microsoft.com/en-us/library/office/cc815908.aspx.

MaillItem.UserProperties can be used from anywhere - Outlook Object Model is Outlook Object Model whether it is used from inside Outlook or externally from Excel. Keep in mind that setting a user property and daving the item will change its last modified date.

If you want to stick to PR_SEARCH_KEY, to be be able to sort on it, you might want to look at Redemption - its RDOFolder.Items.Find / Restrict methods allow PT_BINARY properties in its queries, e.g. "http://schemas.microsoft.com/mapi/proptag/0x300B0102" = '89F75D48972B384EB2C50266D1541099'