Poor Image Resolution with Motion Detection

[Deeks]

Hi. I have multiple Hikvision cameras running through a Hikvision DS-7608NI-E2/8P NVR. I've got the NVR configured to send me an email when it detects motion. The problem is that the attached images are such low resolution (240x320 pixels) that they are of practically no use

Does anyone know how I can increase the resolution of the captured images?

I am using firmware V3.4.90 build 161008 on the NVR. Any advice appreciated!

 

[Geeman]

I arrived here seeking the answer to this very question.
I have DS-7616NI-SP with 8 x DS-2CD2332-I.