(VB.NET) POP3 Verify Signed (S/MIME) Email

Demonstrates how to download and verify digitally signed S/MIME email.

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

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

Dim mailman As New Chilkat.MailMan
Dim success As Boolean

' Set the POP3 server's hostname
mailman.MailHost = "pop.someMailServer.com"

' Set the POP3 login/password.
mailman.PopUsername = "myLogin"
mailman.PopPassword = "myPassword"

Dim sa As Chilkat.StringArray = mailman.GetUidls()
If (mailman.LastMethodSuccess = False) Then
    Debug.WriteLine(mailman.LastErrorText)
    Exit Sub
End If


Dim email As Chilkat.Email
Dim uidl As String

Dim i As Integer = 0
While i < sa.Count

    uidl = sa.GetString(i)

    email = mailman.FetchEmail(uidl)
    If (mailman.LastMethodSuccess = False) Then
        Debug.WriteLine(mailman.LastErrorText)

        Exit Sub
    End If


    Debug.WriteLine(email.From)
    Debug.WriteLine(email.Subject)

    ' The security layers of signed and/or encrypted emails
    ' are automatically "unwrapped" when loaded into
    ' a Chilkat email object.
    ' An application only needs to check to see if an email
    ' was received signed or encrypted, and then examine
    ' the success/failure.  For example:
    If (email.ReceivedSigned = True) Then

        Debug.WriteLine("This email was signed.")

        ' Check to see if the signatures were verified.
        If (email.SignaturesValid = True) Then
            Debug.WriteLine("Digital signature(s) verified.")
            Debug.WriteLine("Signer: " & email.SignedBy)

            ' The certificate used for signing may be obtained
            ' by calling email.GetSignedByCert.
            Dim cert As Chilkat.Cert
            cert = email.GetSignedByCert()
            If (email.LastMethodSuccess = False) Then
                Debug.WriteLine("Failed to get signing certificate object.")
            Else
                Debug.WriteLine("Signing cert: " & cert.SubjectCN)

            End If


        Else
            Debug.WriteLine("Digital signature verification failed.")
        End If


    End If


    i = i + 1
End While



mailman.Pop3EndSession()