I have an email that was received from a person in Costa Rica. But when I did a reverse lookup, it showed Illinois and also Maryland as where the originating IP address was from. Could it b possible for someone in C.Rica to send and email off of a server in the U.S?

I did a reverse IP address lookup on an email received from a "lost family member"(he says he’s in Costa Rica, but we believe he’s in Chicago or thereabouts). When I did the reverse lookup of a recent email, it pointed to Illinois as the email servers source. Is there any possibility that this email could have come from Costa Rica, even though the reverse search showed Illinois as the source email server site? Or is the IP address reverse lookup country specific?

I used www.IP2location.com

Hope this makes sense?
Is the reverse lookup country specific?