Hikvision cameras connected to nvr to send direct email

using gmail settings, in fact these settings were working fine earlier and stopped working once I changed my router.
anyway, I have re-confirmed the email settings as they are perfectly alright in the NVR config.
Moreover, have tried another smtp server which is allocated to me by my ISP. same deal, does not work..
I am really fed up ..
 
Ok I missed the part where it was working previously. I had an issue with the SSL and TLS enables. Are you using the SSL server port 465 or TLS 587? Have you tried the other one mentioned?