If an email is sent without being signed by DKIM, it loses its authenticity and may be treated as spam or phishing by receiving email servers. DKIM (DomainKeys Identified Mail) is an email authentication method that allows recipient mail servers to verify that an email was indeed sent by the domain claimed in the message’s sender address. Without DKIM signature, the receiving mail server has no way to verify the email’s authenticity and may reject it or mark it as spam. This can harm the sender’s reputation and result in their emails being filtered into the recipient’s spam folder or even blocked altogether.
