(PHP Extension) Sending S/MIME Encrypted Email

Sends an encrypted email using the recipient's digital certificate from a .cer file.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux

<?php

include("chilkat.php");
// Use "chilkat_9_5_0.php" for versions of Chilkat < 10.0.0

// 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.
$mailman = new CkMailMan();

// Set the SMTP server.
$mailman->put_SmtpHost('smtp.comcast.net');

// Load the .cer file into a certificate object.
// When sending S/MIME encrypted email, it is the recipient's
// certificate that is used for encryption.  Only the public key
// is needed to encrypt.  The recipient is the only
// one possessing the private key, and therefore is the only
// one able to decrypt.
$cert = new CkCert();
$success = $cert->LoadFromFile('cknotes.cer');
if ($success != true) {
    print $cert->lastErrorText() . "\n";
    exit;
}

// Create a new email object
$email = new CkEmail();

$email->put_Subject('This email is encrypted');
$email->put_Body('This is a digitally encrypted mail');
$email->put_From('Chilkat Support <support@chilkatsoft.com>');
$success = $email->AddTo('Chilkat Blog','admin@cknotes.com');

// Indicate that the email is to be sent encrypted.
$email->put_SendEncrypted(true);

// Specify the certificate to be used for encryption.
$success = $email->SetEncryptCert($cert);

$success = $mailman->SendEmail($email);
if ($success != true) {
    print $mailman->lastErrorText() . "\n";
}
else {
    print 'Mail Sent!' . "\n";
}


?>