a section of an email message that is used by a mail server to route and deliver an email message

a section of an email message, which is usually hidden by most email programs, that contains detailed information about the origination of the message

Information that identifies the sender and recipient of a message, information about how the message was routed through the network, the date and time at which the message was sent, and the subject of the message.

The section of an email message that contains the sender's and recipient's email addresses as well as the routing information.

The first part of an email message containing controlling and meta-data such as the Subject, origin and destination email addresses, the path an email takes, or its priority.

The first part of an email message, including the To, From, Subject, Cc, Bcc, and Attachment fields. This allows the email's sender, receiver and subject to be easily identified.