Hello,
FYI:
Dim MyMapiMessage As MapiMessage = MapiMessage.Load(str, loadopt)
MyMapiMessage.Headers.Set("X-Mailer"...
Dim SignedMessage As MapiMessage = New Email.SecureEmailManager().AttachSignature(MyMapiMessage, MyC…...(2603:10b6:408:111::13) target has only one: BN9PR03CA0398.namprd03...property retention during signing—only after verification or conversion...