(VB.NET UWP/WinRT) Send Encrypted Email to Multiple Recipients

Demonstrates how to create and send an S/MIME encrypted email to multiple recipients. The digital certificate of each recipient is required. The encrypting/sending process uses each recipient's digital certificate (which internally contains the public key). Each recipient decrypts the received email using his/her private key.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

' 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"

' Load each recipient's certificate into a Chilkat certificate object.
' This example loads the certificates from files.  However, the Chilkat
' certificate object provides other means for loading certificates,
' such as from in-memory PEM strings, or in-memory binary DER encoded form, etc.
Dim cert1 As New Chilkat.Cert
Dim success As Boolean = cert1.LoadFromFile("recipient1.cer")
If (success <> True) Then
    Debug.WriteLine(cert1.LastErrorText)
    Exit Sub
End If

Dim cert2 As New Chilkat.Cert
success = cert2.LoadFromFile("recipient2.cer")
If (success <> True) Then
    Debug.WriteLine(cert2.LastErrorText)
    Exit Sub
End If

Dim cert3 As New Chilkat.Cert
success = cert3.LoadFromFile("recipient3.cer")
If (success <> True) Then
    Debug.WriteLine(cert3.LastErrorText)
    Exit Sub
End If


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

email.Subject = "This email is encrypted and sent to 3 recipients"
email.Body = "This is an S/MIME encrypted mail sent to 3 recipients"
email.From = "Chilkat Support <support@chilkatsoft.com>"

' Make each of the certificates available for encrypting the email
' by calling AddEncryptCert for each.
success = email.AddEncryptCert(cert1)
If (success = True) Then
    success = email.AddEncryptCert(cert2)
End If

If (success = True) Then
    success = email.AddEncryptCert(cert3)
End If

If (success <> True) Then
    Debug.WriteLine(email.LastErrorText)
    Exit Sub
End If


' Add 3 recipients to the email (2 TO addresses, and 1 CC address)
success = email.AddTo("Recipient 1","admin@cknotes.com")
success = email.AddTo("Recipient 2","somebody001122@yahoo.com")
success = email.AddCC("Recipient 3","somebody123xyz@gmail.com")

' Indicate that the email is to be sent encrypted.
email.SendEncrypted = True

' Send the encrypted email...
success = Await mailman.SendEmailAsync(email)
If (success <> True) Then
    Debug.WriteLine(mailman.LastErrorText)
Else
    Debug.WriteLine("Encrypted Email Sent!")
End If