IP Address Locations

Is there a directory somewhere that list what IP pools are allocated to
which company/country?

I keep getting masses of emails from people claiming to be in one
country at the time or writing, yet their logic in emails suggests that
they are already in Beijing.

No issue with competitors feeling one out.  However it does waste my
time and if I can get a handle on the truth of the matter - I can craft
my responses accordingly to flush out the chaff from the coal.

?

RF.