It makes sense for system times to be UTC—in fact, I remember lo, these many years ago with my first ISP, the files I downloaded were all time-stamped with UTC time, even though the ISP was a local company. It was kind of disconcerting sometimes to see “files from the future” in the directory listings on my PC
However, time stamps in E-mail headers often are not UTC. I assume they reflect the time zone of the mail server.
BTW, in “Your Control Panel” there is an item called “Localization settings.” It can be set to any time zone. But what does it affect?