In each email is included a text block which contains information that is used to control and transmit the message. This section is called header. Also other meta-data included in the header as the subject, the destination and origin email addresses, the path followed by the email for sending and possibly its priority.
The headers do not usually appear entire from the mail programs. Only specific information such as the subject, the sender and date are visible and formatted to be usable.
Why can someone examine more the header of an email; In fact, there is no particular reason for someone to deal with the other information contained in the header, except if:
- there is a possibility that the email is attempting phishing or spoofing
- someone wants to see the information for the email path to the recipient
