(C++) S/MIME Encrypt .eml without Sending

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#include <CkEmail.h>
#include <CkCert.h>
#include <CkStringBuilder.h>
#include <CkMailMan.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    CkEmail email;

    success = email.LoadEml("c:/temp/email/unencrypted.eml");
    if (success == false) {
        std::cout << email.lastErrorText() << "\r\n";
        return;
    }

    // The email content is encrypted using AES with a 256-bit key, operating in GCM mode, which provides authenticated encryption.
    email.put_Pkcs7CryptAlg("aes-gcm");
    email.put_Pkcs7KeyLength(256);
    email.put_OaepPadding(true);
    email.put_OaepHash("sha256");
    email.put_OaepMgfHash("sha256");

    CkCert cert;
    success = cert.LoadFromFile("c/temps/cert/recipient.cer");
    if (success == false) {
        std::cout << cert.lastErrorText() << "\r\n";
        return;
    }

    email.put_SendEncrypted(true);
    email.SetEncryptCert(cert);

    CkStringBuilder sbSmime;

    // The mailman object applies the encryption by rendering the email according to the instructions (property settings) provided in the email object.
    // No email is sent.
    CkMailMan mailman;
    success = mailman.RenderToMimeSb(email,sbSmime);
    if (success == false) {
        std::cout << mailman.lastErrorText() << "\r\n";
        return;
    }

    success = sbSmime.WriteFile("c:/temp/encryptedEmail.eml","utf-8",false);
    if (success == false) {
        std::cout << mailman.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Success!" << "\r\n";
    }