Somebody in my company is being subject to phishing. My first suggestion was just to change the password. However after awhile I received a fake mail from her address again. 

Looking at the raw source of the email I found that there is another person's email in X-Sender-ID and I'm wondering who that might be. Is that the person who sent the email or can it be an account that has been hijacked? (I replaced the email with "somebody@host.com")

```
X-Virus-Scanned: OK
Received: by smtp5.relay.iad3a.emailsrvr.com (Authenticated sender: somebody-AT-host.com) with ESMTPA id DF2788019C;
    Fri, 21 Nov 2014 07:54:42 -0500 (EST)
X-Sender-Id: somebody@host.com
Received: from smtp.emailsrvr.com ([UNAVAILABLE]. [2.133.148.211])
    by 0.0.0.0:587 (trex/5.3.2);
    Fri, 21 Nov 2014 12:54:46 GMT

```

What is X-Sender-ID? And what is the email it contains?