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…...OUTLOOK.COM ([fe80::ae6e:b9:aa98:e197])...AS8P193MB1879.EURP193.PROD.OUTLOOK.COM (2603:10a6:20b:3fd::14)...