UTM v9 notification does not work after upgrade isp from comcast to at&t

my UTM v9 notification was working fine, my email is gmail.

Yesterday, I upgrade my internet service from comcast to at&t gbit fiber, then I connected UTM v9 to the new service, everything seems working fine, except I have no more email notification from UTM. Anybody has idea what should I check on that? many thanks.


I resolved it, I adjusted smtp port from 25 to 587, I think my at&t router block outbound port 25.
[edited by: TingYu at 8:51 PM (GMT -7) on 20 Jul 2021]