Look for the From: line at the start of the email. This will display the sender's name and email address:
In most email programs this line will display the sender's name.
You may need to hover your mouse over the name or - tap the name if you are on mobile - to view the full sender info including their email address.
For example, in Gmail, you can click the dropdown arrow next to your name at the top of an email,
and a popup window will display with the sender's name and email address, beginning with From:
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