PHP

Send DKIM Signed Email

See more DKIM / DomainKey Examples

Demonstrates how to send DKIM signed email. Chilkat2 PHP

<?php

use Chilkat2\BinData;
use Chilkat2\Dkim;
use Chilkat2\Email;
use Chilkat2\MailMan;
use Chilkat2\PrivateKey;

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

$mailman = new MailMan();
$dkim = new Dkim();

// SMTP server settings...
$mailman->SmtpHost = 'SMTP_DOMAIN';
$mailman->SmtpUsername = 'SMTP_LOGIN';
$mailman->SmtpPassword = 'SMTP_PASSWORD';
$mailman->SmtpPort = 465;
$mailman->SmtpSsl = true;

$email = new Email();

$email->Subject = 'This is a test';
$email->Body = 'This is a test';
$email->From = 'Chilkat Support <support@chilkatsoft.com>';

// Add some recipients (BCC recipients are added below)
$email->AddTo('Chilkat Software', 'chilkat_software@yahoo.com');
$email->AddTo('Chilkat Admin', 'admin@chilkatsoft.com');
$email->AddCC('Chilkat Admin', 'admin@chilkat.io');

// When sending an email with a DKIM signature, the MIME
// of the email must not be modified prior to
// or during the sending process.  Therefore, the MIME of the
// email is assembled, the DKIM signature is added, and then
// SendMimeBd is called to send the email.

// First get the MIME of the email.  Calling RenderToMimeBd
// causes the email to be signed and/or encrypted if those options
// have been selected.  The MIME returned by RenderToMimeBd
// is the exact MIME that would've been sent if SendEmail was
// called.  We'll add a DKIM signature header to this MIME and then send...
$bdMime = new BinData();
try {
    $mailman->RenderToMimeBd($email, $bdMime);

    // To create a DKIM signature,
    // you'll need to provide the following:
    // (1) An RSA private key in any common file format.
    // (2) The domain name (typically the same domain
    // as the sender of an email).
    // (3) A selector for the domain name -- an arbitrary string
    // to identify the matching public key in DNS.

    // To allow an email recipient to verify the DKIM signature via an
    // external email client supporting DKIM or using other software,
    // you will need to create a DNS record with the selector
    // and matching public key.  This example does not provide
    // information about DKIM DNS record creation.
    // (Chilkat does not provide an API for creating DNS records.
    // Creating the DKIM DNS record is something you would do
    // manually.)

    // Set the domain and selector:
    // You'll need to provide your own values here..
    $dkim->DkimDomain = 'chilkatsoft.com';
    $dkim->DkimSelector = 'brisbane';

    // Load a private key from any common RSA private key
    // format, such as DER, PKCS8, PEM, XML, etc.
    // The LoadDkimPkFile method automatically detects
    // the file format and reads it appropriately.
    // If a password is not required, you'll still need to provide
    // an empty password string argument, but it is ignored.
    $password = 'passwd';
    $privKey = new PrivateKey();
    $privKey->LoadAnyFormatFile('qa_data/pem/rsa_passwd.pem', $password);

    $dkim->SetDkimPrivateKey($privKey);

    // Add the DKIM-Signature header to the MIME in bdMime
    $dkim->DkimSign($bdMime);

    // If desired, examine the MIME of the email being sent.
    $bdMime->WriteFile('qa_output/dkimSigned.eml');

    // ---- Prepare to send the email contained in bdMime ---

    // To send to multiple email addresses, the strRecipients should be set to a comma-separated
    // list of email addresses.

    // Note: This is where we can add additional BCC addreses.
    // Here we are adding "chilkat.support@gmail.com" as an additional BCC address.
    // Notice that the 1st three email addresses are NOT BCC because these email addresses
    // appear in the MIME header of the email (in the "To" and "CC" header fields).
    // A BCC email address does not appear in the MIME, and thus the non-BCC recipients cannot see
    // that the email was also sent to the BCC address.  (BCC means "blind carbon copy")
    $strRecipients = 'chilkat_software@yahoo.com, admin@chilkatsoft.com, admin@chilkat.io, chilkat.support@gmail.com';
    $strFrom = 'support@chilkatsoft.com';

    $mailman->SendMimeBd($strFrom, $strRecipients, $bdMime);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

try {
    $mailman->CloseSmtpConnection();
} catch (\Chilkat2\Exception $e) {
    echo "Connection to SMTP server not closed cleanly.\n";
}

echo "DKIM Signed Mail Sent!\n";