@dazcuenaga in HW v3 I presume you're using WDS feature to do this. Have you followed this guide ?

@Toople Regarding SMTP settings you can try with Google or Yahoo. If they don't work for you then try using other SMTP service - there's a lot of them. As for the 'Probing DNS' message follow the...

@mohank Have you set static wireless channel on the main router, when setting up the WDS ? If wireless channel is set to Auto, when the main router changes the channel (due to interference, reboot,...

@Martyn7 Use this guide for configuring C7 in AP mode. If you are receive=ing an error message in the Tether app then use a browser.

@Toople Most probably, your DVR needs that port. Here - https://www.cctvcameraworld.com/port-forwarding-for-dvr-and-nvr/ you can read what could it be or better check your DVR manual or manufacturer...

@sanikbug2k18 Here's the procedure in such cases. If after that procedure you still can't access the device then contact your local support and explain these details to be advised.