Warn before sending emails to external domains in Outlook

Question

How can you get Outlook to warn you if you are about to send and email to an external domain?

Sending large amounts of emails everyday it is always possible

Answer 1

1. Add the below code to the Application_ItemSend event in Outlook & change the domain to your own

2. Change the Macro Security to either (Notifcations for all macros or Enable all macros)

This will provide you with a warning before sending if 1 or more of your TO,CC or BCC address is not in your domain (eg below @mycompany.com.au)

Private Sub Application_ItemSend(ByVal Item As Object, Cancel As Boolean)
    Dim recips As Outlook.Recipients
    Dim recip As Outlook.Recipient
    Dim pa As Outlook.PropertyAccessor
    Const PR_SMTP_ADDRESS As String = "http://schemas.microsoft.com/mapi/proptag/0x39FE001E"
    Set recips = Item.Recipients
    For Each recip In recips
        Set pa = recip.PropertyAccessor
        If InStr(LCase(pa.GetProperty(PR_SMTP_ADDRESS)), "@mycompany.com.au") = 0 Then
            If MsgBox("Send mail to external domain?", vbYesNo + vbQuestion + vbMsgBoxSetForeground, "Check Address") = vbNo Then
                Cancel = True
                Exit Sub
            Else
                Exit Sub
            End If
        End If
    Next
End Sub