hello
what is smtp server in hotspot setup ?
you can add website name in firewall rule then accept it.I am using 6.30 now.if you update your router board to routeros 6.36 then you can do it.
If I upgrade to 6.36, how to setup ?
/ip firewall nat
add action=dst-nat chain=dstnat disabled=no dst-address=public-ip dst-port=7000 in-interface=ether1-gateway protocol=tcp to-addresses=172.16.20.253 to-ports=7000