Email function stopped working on old DAHUA DVR's

Hi Guys

Anyone else experiencing a problem on the old Dahua CIF/D1 machines were the email function just stopped working, all my customers have the same problem started about a month ago, I know its old DVR's and my recommendation is to upgrade to HDCVI but not all of my customers have the money to upgrade,all the new DVR's work 100% with the same settings, my guess its probably a security upgrade on the email servers that the older models firmware doesn't support, but that's just speculating.

I have tried 5 different smtp servers and all does the same on the older models, all work on the newer models.

If anyone has got a older cif/D1 model can you test for me ? please PM me if you need any assistance doing the setup

any help will be appreciated

Regards