A tough one. The problem is that all email is a gentleman's agreement - everyone agrees to more or less the same standards, everyone agrees to pass messages along in a "civilized" manner, and everyone agrees to (hopefully) not snoop or stomp on messages.
The originating IP address in the header claims that it did originate from the same machine (unless, of course, the same machine is behind a NAT):
X-Originating-IP [186.120.49.100]
However, that X-
in front of the line indicates it's a non-standard extension, so while that line carries some weight with regard to verification, it doesn't carry a 100% certainty with me.
Also, the traceroute at the top of both pages seems to implicate that it was the same mail server (or again, servers hosted behind a NAT firewall).
The likelihood is very high that it was the same server. But there isn't a 100% assurance that it was the same machine.
At least same IP address if the computer cannot be determine. – ray sn0w – 2015-08-11T14:05:41.867