Full email message headers provide invaluable information when trying to track down a problem. Just a few of the items included in the headers are:

• The server from which an incoming email originated
• The actual address from which the message was sent
• The message’s intended recipient
• Whether the message was accepted or rejected by the recipient’s mail server
• If the recipient’s mail server rejected the message, the reason for that rejection
• Any messages returned by the mail server

This guide will show you how to view full headers in several popular email clients and web services. Once the full headers are in view, you can copy and paste them for your own reference or to include them when contacting Heroic Support®.

Mozilla Thunderbird

• Open the message in its own window by double clicking on it in the list of messages.
• In the menu bar, select View, then Headers, and click All.
• Alternatively, you may be able to click on View followed by Message Source.

Mac OS X Mail

• Open the message in its own window by double clicking on it in the list of messages.
• In the menu bar, click on View, then Message, then All Headers (or Raw Source on older versions of Mail).

Outlook 2016, 2013, and 2010

• Open the message in its own window by double clicking on it in the list of messages.
• Click on the File tab.
• In the File window, click Properties.
• The Internet headers section contains the full email headers.

Windows Mail/Windows Live Mail

• In the list of messages, right-click on the message in question and choose Properties.
• In the Properties window, click on the Details tab.
• The headers will be displayed in the section labeled Internet headers for this message.

Outlook.com Web Interface

• Right-click on the message while viewing it in your inbox.
• On the menu that appears, click on View Source.

Gmail Web Interface

• Open the message by clicking on it in the list of messages.
• Click on the More icon (the small downward-facing arrow next to the Reply button at the top right of the message).
• On the menu that appears, click on Show original.

Yahoo Mail Web Interface

• Open the message in question by clicking on it in the list of messages.
• Under the More menu above the message, click on the link marked View Full Header.

Horde Webmail

• Open the message by clicking on it in the list of messages.
• Click on the link marked Show All Headers or, on newer versions of Horde, select View Sourceunder Other Options in the preview pane. View Source also is available at the top-right of the full message view.

RoundCube Webmail

• Open the message by double-clicking on it in the list of messages.
• Click on the link marked Message Source. Newer versions of RoundCube have a downward-facing arrow that displays Toggle raw message headers when you move your mouse over it. The icon is at the bottom of the message header section, to the far right of the date field.

SquirrelMail Webmail

• Open the message by clicking on it in the list of messages.
• Click on the link marked View Full Header in the Options section at the top of the message.