hmm, ok we changed a few setting for DNS and that is fine, they are the BT Broadband DNS settings so unless you find something weird happening that is out of the norm those settings should be fine there
the BT hub from what i can see is set correctly, the NVR does appear to be set correctly
stupid time now and grabbing at straws, we have a couple of things left to try
reboot the NVR but i guess you already tried that
hopefully using the smtp2go account you have sent and received emails from your pc, phone or smtp2go web page just to verify emails are being received and sent correctly
looking at the smtp2go website there are alternate ports that can be used in case of issues, you will need to change the port number in your NVR email settings and then do as you did before and add them to your router ( Device CCTV ) list so they can talk to the outside world, the ports offered are 8025, or 587
defo worth a shot at trying different ports but apart from that i am as stumped as you
ahh its no probs, i am no expert, the reason we are all here is to help and learn, and anyway the Mrs was watching some god awfull hospital program on the box so i got out of it and came and sat here on my pc for a while
Oh and dont worry too much about email failing pop up when hitting the test button, i get that but have no issues with email
Also what event are you expecting emails from ??