Rt & getmail and upstream with nginx

im strugling to get RT fully functional with email but i get different nginx errors about upstream like

upstream prematurely closed connection while reading response header from upstream quest: “POST /REST/1.0/NoAuth/mail-gateway HTTP/1.0”, upstream: “fastcgi://[::1]:5000”,
or
connect() failed (111: Connection refused) while connecting to upstream request: “POST /REST/1.0/NoAuth/mail-gateway HTTP/1.0”, upstream: “fastcgi://127.0.0.1:5000”

and sometimes mails get through to rt5 … and nginx doesnt work if i dont use localhost:5000 for passcgi if i use ip values i get 502 via browser. so i understand there are some configuration files out of order but dont know which …whole thing is behind reverse proxy and with remote mail server