DomainKeys Identified Mail (DKIM) is a method of email authentication to detect forged sender addresses which are often used in phishing and email spam. DKIM allows the receiver to verify that an email claimed to have originated from a particular domain was authorised by the owner of that domain.<br />
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<strong>Note:</strong> You can only enable this option if you have the <a href="https://secure.php.net/manual/en/book.openssl.php" target="_blank"><code>openssl</code></a> extension installed and enabled.