If you are confused about any email you received in your inbox and you need to identify the sender please follow these steps:
1. click on the reply icon
2. place your cursor on the (user)name of the sender (who is by now intending receiver) for 5 seconds. .

The (user)name and the email will appear. With this, you can see the email address of the sender.
For instance, if you received an email from first bank asking you to update your account or BVN details, by following the above steps you would know if the email was sent from a yahoo or gmail account.

Hope it helps.

Thank you for reading.