Important, so taking any one of them for granted is guaranteed to hurt your campaign results. Still, some components of your email marketing campaigns get a lot more attention than others. Many marketers take years to master the art of email copying. Others focus on analysis, striving to find the best possible day and time to send their message for maximum opens. While there is no doubt that these elements are important factors, don't forget the one that will make the first impression of your message: The email header. What is an email header? In terms of content, there are two main components of any email message. There's the body of the message itself, often where the company mailing list puts most of their communication and effort, and there's the header of the email, the part above of the body of the email. The header includes: sender the receiver the date the object the server responsible for the transmission picture (optional) every email program will allow you to see the entire header Of the email, but most mostly show the subject line, sender, and date sent by default. Legal requirements for your email headers there are certain legal requirements that you must follow with your email headers. In the united states, there is the can-spam law. In the uk, the privacy and electronic communications regulations 2003 outline the laws regarding email headers. Casl laws in canada do the same. Almost every country has its own version of these types of legal requirements.