An email is series of “headers” such as To: and From: and Subject: which tell us useful things. When we view our email, some program has taken these headers and used then to show us our email in a readable way. There are extra headers that such programs don’t show us.
When analysing an email, it’s important to see all the headers, even the ones we don’t normally see.
If you’re sending an email to me, please forward it to me as an attachment, so that I get all the headers.
In the latest update to Microsoft 365 (previously Office 365) this is quite easy: view the email in Outlook by double-clicking it (don’t just preview it) and you’ll see this:
Click on the three dots, and choose “Forward as Attachment”
Then fill in the name of who you want to send it to, and send it off.
You can see how to do it in previous versions of Outlook here.
With web mail (where you look your email through a web browser (for example Chrome, Edge, or Safari) rather than an email program, you’ll need to download the email first. Once it’s been downloaded it’s a file on your computer and you can send it to anyone, just like any file. Beaware that some people may not be able to receice a mail attachment, as they could be virus-infected.
Here’s how to download an email using the Gmail web interface. First display the email, and look for this in the top-right
Click on the three dots, and then click on “Download message”.
Finally, if you just want to view the headers, this page shows you how.