I've installed one of these and client is having issues with sending email notifications. For a few months it was working just fine and the other day it just stopped. No settings were changed. I have signed in to try my emails with correct settings and I keep getting test failed.

Everything else is working just fine, including his DNS and iphone app vieweing

(has latest firmware)

any ideas? didnt call tech support yet, was hoping for a quick fix. odd issue