(VB.NET) Send Signed Email using PFX File (long version)

Demonstrates how to send a signed email using a digital certificate w/ private key stored in a PFX file.

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' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

' The mailman object is used for sending and receiving email.
Dim mailman As New Chilkat.MailMan

' Set the SMTP server.
mailman.SmtpHost = "smtp.mymailserver.com"

' Create a new email object
Dim email As New Chilkat.Email

email.Subject = "This email is signed"
email.Body = "This is a digitally signed mail"
email.From = "Chilkat Admin <admin@chilkatsoft.com>"
Dim success As Boolean = email.AddTo("Chilkat Support","support@chilkatsoft.com")

' Indicate that the email should be sent signed.
email.SendSigned = True

' Load a PFX file into a certificate store object.
' Then locate the certificate matching the  sender's email address,
' and use it for signing.
' (a PFX file may contain more than one certificate.)
Dim certStore As New Chilkat.CertStore
' The 1st argument is the path of the PFX file, the 2nd arg is the 
' PFX file's password:
success = certStore.LoadPfxFile("/pfx_files/chilkatsoft_secret.pfx","secret")
If (success <> True) Then
    Debug.WriteLine(certStore.LastErrorText)
    Exit Sub
End If


Dim cert As Chilkat.Cert = certStore.FindCertBySubjectE("admin@chilkatsoft.com")
If (certStore.LastMethodSuccess = False) Then
    Debug.WriteLine(certStore.LastErrorText)
    Exit Sub
End If


' Alternatively, if a PFX file is known to contain a single certificate,
' you may load it directly into a Chilkat certificate object.
' This snippet of source code shows how:
Dim cert2 As New Chilkat.Cert
' The 1st argument is the filename, the 2nd arg is the 
' PFX file's password:
success = cert2.LoadPfxFile("/pfx_files/chilkatsoft_secret.pfx","secret")
If (success <> True) Then
    Debug.WriteLine(cert2.LastErrorText)

    Exit Sub
End If


' This example will use the cert from the certStore...
success = email.SetSigningCert(cert)

' Signed email can be sent in two different ways.  
' In a multipart/signed email, the signature is attached as a separate MIME part.
' In an opaque email (signedData) the content of the email is encapsulated within the signature
' and the email is sent as "application/pkcs7-mime". 
' Either should be fine, but some receiving systems might require one or the other..
mailman.OpaqueSigning = False

' Send a signed email.
success = mailman.SendEmail(email)
If (success <> True) Then
    Debug.WriteLine(mailman.LastErrorText)
Else
    ' The LastErrorText property provides information
    ' even when successful.
    Debug.WriteLine(mailman.LastErrorText)
    Debug.WriteLine("Mail Sent!")
End If