Wide-ranging IP-city results?

I use IP-city websites to tell me where my friends are communicating from via e-mail (some e-mail services give you the IP address in the e-mail). Usually, they are fairly consistent, with only minor discrepencies (i.e., they might show a specific town or the closest major city). After getting an IP that indicated only a certain foreign nation (no city), I looked it up on a number of different IP-city-finder websites, and was stunned at the wide variety of results I got: Two countries; five different cities! I stopped after seeing the variety. Why aren't the results consistent?

STEVEN F2019-08-01T22:40:40Z

ALL e-mails include the IP address of the SERVER. That is a MANDATORY part of the headed format.
The websites you use are inherently unreliable because IP addresses ARE NOT assigned by physical location.