hi, been following the thread with interest, I have one of these brought from xinray off aliexpress.com a year or so ago:
Model DS-2CD3132-I
Serial No. DS-2CD3132-I20150402CCCH5xxxxx
Firmware Version V5.2.5 build 141201
Encoding Version V5.0 build 140714
It was using gmail and ssl and stopped working back on July 7th. To add to the annoyance my isp blocks port 25...
Anyway I have a work around of sorts, I thought I'd share, it might help others. My one camera is on same network as synology NAS - the nas records the video captured etc. I have setup the camera to use port 25 and send to the NAS running its built in mail server software, the software on the NAS (postfix in back-end) simply forwards the mail using TLS to gmail and my alerts are back in business, when my NAS is running. I think a similar setup could be achieved by any other postfix capable device on your network, raspberryPi perhaps etc. I can perhaps share screenshots of setup if it helps anyone. My Nas is on a schedule to turn on in the morning when I leave for work and I tend to turn it off when home at night, so this method should actually work out quite well, I can leave camera on all night now, visitors will see the IR lights, but I am not spammed etc...