Email message headers provide a list of technical details about the message, such as who sent it, the software used to compose it, and the email servers that it passed through on its way to the recipient.
About message headers
After a message is sent, it is processed by the Microsoft Exchange Server or email server used by your organization or Internet service provider (ISP). If the message is for someone who does not have a mailbox on your email server, the server forwards the message to another email server. The message is forwarded from server to server. Frequently, the message passes through several email servers until it reaches the email server on which the recipient of the message has a mailbox.
From the time when the message is first created, information about it is added to a hidden section of the message known as the Internet header. The information includes technical details, such as who created the message, the software used to compose it, and the email servers it passed through on its way to the recipient. These details can identify problems with the message or help discover the sources of unsolicited commercial messages.
View message headers
In an open message, click the File tab.
Header information appears in the Internet headers box.
Note: The practice of providing false information in message headers is a growing problem. This is also known as spoofing. For example, a message might indicate that it is from Eric Lang at Alpine Ski House (firstname.lastname@example.org) when it is actually from a bulk email service that promotes schemes to get rich quickly. Therefore, before you send a complaint response to someone about his or her message, remember that the header information might be forged.