I’m using this one: http://www.kolkatapolice.gov.in/reportcrime_new.asp
I did get an error about malicious tags - it’s for XSS “protection”.
If the message contains these characters, it won’t work (you also can’t have a script tag, but scammer.info has the same “protection” as Kolkata, so I can’t write one):
;':
I just removed any of those.
It is unclear how phone numbers should be formatted, and no matter how I format my US phone number, it wouldn’t work. I eventually determined that your phone number can’t have spaces or a plus to indicate country code. 
But even after I fixed these, it just sent me here:
How do I fix this?