How to find out who the email came from?

Question

Computer networks

Is there a way to find out who sent you an email? Let's say the options are:
1. It was sent to you from a well-known mailer (google / mail, etc.)
2. Sent from your server.
How can be tracked? In which direction to dig?

Answer 1

By sequence of Received headers and From header

Received: by 10.194.78.40 with SMTP id y8csp1449227wjw;
        Sat, 20 Jun 2015 22:23:48 -0700 (PDT)
Received: from smart1.russianpost.ru (smart1.russianpost.ru. [91.215.36.115])
        by mx.google.com with ESMTP id wd2si13339101lbb.123.2015.06.20.22.23.47
        for <***@gmail.com>;
        Sat, 20 Jun 2015 22:23:48 -0700 (PDT)
Received: from [10.6.40.76] (HELO VEGA)
  by smart1.russianpost.ru (CommuniGate Pro SMTP 4.2.10)
  with ESMTP id 50561940 for ***@gmail.com; Sun, 21 Jun 2015 08:23:28 +0300
From: [email protected]

If you look at the time, then the chain of passage is 10.6.40.76 -> smart1.russianpost.ru -> mx.google.com -> 10.194.78.40

Answer 2

You need to look at the headlines. The From header is responsible for the sender.