MS Outlook VBA - When is a MailItem not a MailItem?

Question

I have written a message handler function in Outlook's Visual Basic (we're using Outlook 2003 and Exchange Server) to help me sort out incoming email. It is working for me, except sometimes the rule fails and Outlook deactivates it. Then I turn the rule back on and manually run it on my Inbox to catch up. The rule spontaneously fails and deactivates several times a day. I would love to fix this once and for all.

I have

Answer 1

have written a message handler function in Outlook's Visual Basic (we're using Outlook 2003 and Exchange Server) to help me sort out incoming email. It is working for me, except sometimes the rule fails and Outlook deactivates it. Then I turn the rule back on and manually run it on my Inbox to catch up. The rule spontaneously fails and deactivates several times a day. I would love to fix this once and for all.

Here is the code stripped of the functionality, but giving you an idea of how it looks:

   Public WithEvents myOlItems As Outlook.Items

   Public Sub Application_Startup()
       ' Reference the items in the Inbox. Because myOlItems is declared
       ' "WithEvents" the ItemAdd event will fire below.
       ' Set myOlItems = Outlook.Session.GetDefaultFolder(olFolderInbox).Items
       Set myOlItems = Application.GetNamespace("MAPI").GetDefaultFolder(olFolderInbox).Items
   End Sub

   Private Sub myOlItems_ItemAdd(ByVal Item As Object)
       On Error Resume Next
       If TypeName(Item) = "MailItem" Then
           MyMessageHandler Item
       End If
   End Sub

   Public Sub MyMessageHandler(ByRef Item As MailItem)
       Dim strSender As String
       Dim strSubject As String

       If TypeName(Item) <> "MailItem" Then
           Exit Sub
       End If

       strSender = LCase(Item.SenderEmailAddress)
       strSubject = Item.Subject

       rem do stuff
       rem do stuff
       rem do stuff
   End Sub

One error I get is "Type Mismatch" calling MyMessageHandler where VB complains that Item is not a MailItem. Okay, but TypeName(Item) returns "MailItem", so how come Item is not a MailItem?

Another one I get is where an email with an empty subject comes along. The line

strSubject = Item.Subject

gives me an error. I know Item.Subject should be blank, but why is that an error?

Thanks.

Answer 2

My memory is somewhat cloudy on this, but I believe that a MailItem is not a MailItem when it is something like a read receipt. (Unfortunately, the VBA code that demonstrated this was written at another job and isn't around now.)

I also had code written to process incoming messages, probably for the same reason you did (too many rules for Exchange, or rules too complex for the Rules Wizard), and seem to recall running into the same problem you have, that some items seemed to be from a different type even though I was catching them with something like what you wrote.

I'll see if I can produce a specific example if it will help.

Answer 3

if it is written with double ll ^^