Want to discover hidden information about an email, possibly retrace its path to you? Find out here how to view all header lines for an email in Apple Mail for Mac.
First, a Man Stands in a Barn
One afternoon, a man stood in Philipp Reis’s barn in Friedrichsdorf, north of Frankfurt in Germany. He had a book in his hands and a wooden ear (on a stick) in front of his face.
Sentence after sentence, he meticulously spoke into the ear. This was the first public demonstration of Reis’s telephone, after all. The wooden ear was equipped with an artificial eardrum (made from a rabbit’s bladder it seems). The drum translated the words into electrical signals by moving a needle that opened and closed, I gather, a circuit as the bladder vibrated.
Now, want to see what the metaphorical needles recorded when an email you have received? You can look at their transcriptions in the email’s headers:
How to View the Email Header in Apple Mail on a Mac
In the Message Window
Time needed: 2 minutes
To view full header lines for an email in macOS Mail on a Mac:
- Open the email message whose headers you want to examine.
Here or there: You can open the email in the Apple Mail for Mac preview pane or in its own window.
- Select View | Message | All Headers from the menu.
Default headers: With all header lines visible, the menu item becomes Default Headers.
Apple Mail keyboard shortcut: You can switch between showing full and restricted default headers by pressing Command Shift H. - Find the expanded set of email header lines underneath the default header area and atop the message text.
Gray. The header lines will display in gray.
Almost all: Note that header lines already displayed as default headers (sender, recipient, date, subject,…) are not repeated; to get or copy all header lines, you can use the email source (see below).
All Header Lines in Email Source Format with Mac Mail
To access the full header as it appears in the email source with Apple Mail for macOS:
- Open the message for which you want to access email headers in Mail.
- Select View | Raw Source from the menu.
Mail keyboard shortcut: You can press Command Option U to open the message source. - Find the full headers in their original order at the top of the Source of <Email Subject> window.
How far: The headers end at the first fully empty line from the top.
How to View the Email Header in Apple Mail on a Mac: FAQ
Can I open the headers for multiple messages at once?
No.
Mail on a Mac lets you open the full header and source views only for a single email at a time.
Can I set full headers to be the default?
No.
Apple Mail will not always revert back to standard header display as soon as you switch to or open a different message—or the same email again.
(How to see all header lines for an email in Apple Mail on a Mac tested with macOS Sonoma 14.3 and Ventura 13.4; updated March 2024)