e-mail notication in wsus

My WSUS server works fine …
The client Syn perfectly…

I tried to setup email notification on wsus…
The test e-mail reach the inbox.

Its seems that it can System.Net.WebException: Unable to connect to the remote server —> System.Net.Sockets.SocketException: No connection could be made because the target machine actively refused it

I also decided to check my event viewer …
I find this:
core
event id 10052
failed mailed notiification

Thanks for your help !!!!