Dedicato a chi dimentica di allegare i file prima di mandare un'email. Testato con successo su Outlook 2016 (16.0.14326.20706)

AttachmentReminder.cls

'  Outlook 2016: Attachment Reminder
'  -----------------------------------------------------------------------------------------------------------
'  Author:          GSolone
'  Version:         0.1
'  Last modified:   21-01-2022
'  Credits:         https://www.slipstick.com/outlook/email/attachment-missing-from-outlook-message/
'                   https://stackoverflow.com/questions/40934390/how-to-check-for-attachment-when-sending-an-email
'  ------------------------------------------------------------------------------------------------------------
'  UPDATES:
'   -

Private Sub Application_ItemSend(ByVal Item As Object, Cancel As Boolean)
Dim vList As Variant
Dim i As Integer
wList = Array("attached", "attachment", "allego", "allegato", "allegata", "allegati")

For i = 0 To UBound(wList)
    If InStr(1, Item.Body, LCase(wList(i)), vbTextCompare) > 0 Then
        answer = MsgBox("Non trovo allegati in questa email, la mando comunque?", vbYesNo + vbQuestion, "Attachment Reminder")
        If answer = vbNo Then Cancel = True
        Exit Sub
    End If
Next i

If Item.Attachments.Count > 0 Then
 For Each oAtt In Item.Attachments
    Debug.Print oAtt.Size
      If oAtt.Size < 5200 Then
        GoTo NextAtt
       Else
       answer = MsgBox("Non trovo allegati in questa email, la mando comunque?", vbYesNo + vbQuestion, "Attachment Reminder")
       If answer = vbNo Then Cancel = True
      End If
NextAtt:
 Next oAtt
End If
End Sub