Morning all,
I wrote a small guide on our own forums recently regarding how to resolve this Gmail issue, as per Hikvision's own instructions. It resolved the issue for us in the office on a Hikvision DS-7716NI-I4-16P, DS-7608NI-E2-8P and various 3MP / 4MP Hikvision cameras running v5.4.0 - we've been receiving email alerts without failure for a couple of weeks now.
It involves creating an app-specific password for your NVR within your Google account settings, or in the case of a standalone camera simply updating to v5.4.0
We're receiving some conflicting reports from our customers. Many are saying that the above process resolved Gmail email alerts for them absolutely fine. Others however are saying that the fix didn't work for them.
I'd appreciate if you could give it a try and post back your results so I can get a greater understanding of how reliable the fix is.
Apologies - I wouldn't ordinarily plug our own forum here, but this is causing me no end of headaches, as I'm sure you can all relate!