(.NET Core C#) POP3 Verify Signed (S/MIME) Email

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

Note: This example requires Chilkat v11.0.0 or greater.

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

bool success = false;

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

Chilkat.MailMan mailman = new Chilkat.MailMan();

// Set the POP3 server's hostname
mailman.MailHost = "pop.example.com";

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

Chilkat.StringTable stUidls = new Chilkat.StringTable();
success = mailman.FetchUidls(stUidls);
if (success == false) {
    Debug.WriteLine(mailman.LastErrorText);
    return;
}

Chilkat.Email email = new Chilkat.Email();
Chilkat.Cert cert = new Chilkat.Cert();

int count = stUidls.Count;
int i = 0;
while (i < count) {
    // Download the full email.
    success = mailman.FetchByUidl(stUidls.StringAt(i),false,0,email);
    if (success == false) {
        Debug.WriteLine(mailman.LastErrorText);
        return;
    }

    Debug.WriteLine(Convert.ToString(i));
    Debug.WriteLine("From: " + email.From);
    Debug.WriteLine("Subject: " + 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) {

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

        // Check to see if the signatures were verified.
        if (email.SignaturesValid == true) {
            Debug.WriteLine("Digital signature(s) verified.");
            Debug.WriteLine("Signer: " + email.SignedBy);

            success = email.LastSignerCert(0,cert);
            if (success == false) {
                Debug.WriteLine(email.LastErrorText);
                return;
            }

            Debug.WriteLine("Signing cert: " + cert.SubjectCN);
        }

    }
    else {
        Debug.WriteLine("Digital signature verification failed.");
    }

    i = i + 1;
}

mailman.Pop3EndSession();