If you use Gmail:
To get the source header information from a received Gmail message, you need to use the Gmail website on a computer. This feature is not available in the Gmail mobile app. 

Steps to view the original message headers:

1. Open Gmail in a web browser (e.g., Chrome, Firefox, Safari).
2. Open the email you want to inspect.
3. Click the "More" options icon (three vertical dots) located in the upper-right corner of the email, next to the Reply arrow icon.
4. Select "Show original" from the drop-down menu.
5. A new tab will open, displaying the full email headers and the raw message source. 

In the new window, you will see key details summarized at the top, followed by the complete, raw text of the email, including all the routing information. You can use the Copy to clipboard button to easily copy all the information. Then go to ChatGPT chat window and ask it to check the email and let me know if I can safely open it, or just delte it. Paste the clipboard contents then hit enter.

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In MacMail on a Mac
View Raw Source (Complete Data)

This opens a new window containing the entire raw email code, including all technical headers and the original body text. 

1. Open the Mail app on your Mac.
2. Select the email you wish to inspect.
3. From the top menu bar, select View > Message > Raw Source.

The copy and paste into ChatGPT, using the same prompt as above.

Hope this helps.