Email headers provide the necessary information about the senders or originating source. There can be various MTAs (Mail Transfer Agents) or intermediary email servers to rely on the message. The most important email headers contain “received, Authentication-Results, DKIM-Signature, From and Message-ID”. The following screenshot contains the message header of a scam or marketing email. The header values are defined inside the RFC and they cannot be changed. Although, the email services holders are able to modify the header in blue colors. These headers are also known as options headers represent by “x-“.