How Outlook displays From and To headers
The header of an email message provides a list of technical details about the message, such as the sender's information, software used to create it, and the email servers it passed through on its way to you.
Why would I need to view the headers?
Sometimes, you may experience delivery issues with your Mailing List email. Often, the problems can be uncovered by inspecting the email message headers.
Most of the time, only an administrator or someone from Tech Support/Helpdesk will need to view internet headers for a message.
How do I find headers in Outlook desktop?
According to Microsoft, please use the following steps:
- Double-click an email message to open it outside of the Reading Pane.
- Click File > Properties.
- Header information appears in the Internet headers box.
TIP: You can highlight the information in that box, press Ctrl+C to copy, and paste it into Notepad or Word to see the entire header at once.
How do I find headers in Outlook using a browser or Outlook.com?
According to Microsoft, please do the following:
- Select the "3 dot" menu at the top of the message window and choose View message source.
More help from Microsoft
For more help, please see this post from Microsoft Support.
For those of you with a technical side, this post includes an example of header details and how to interpret it. Have fun!