Sounds like he wants to perform TFTP reset without accessing the camera - ie. powering it over PoE rather than attaching 12V supply.
I've only ever performed TFTP via 12V / direct to PC. Not tried with PoE switch before
Hikvision cameras (and I'm assuing NVRs too) don't support TLS authentication
So for example, a Yahoo address won't work - as this forces TLS as far as I know.
Gmail offers SMTP without TLS, I use SSL (port 465) and this works perfectly.