SMTP Server

Edit tasxs.service.dll.config

<system.net>
   <mailSettings>
     <smtp deliveryMethod="Network" from="yyy@xxx">
       <network host="10.0.0.5" />
     </smtp>
   </mailSettings>
 </system.net>

Network settings: https://docs.microsoft.com/en-us/dotnet/framework/configure-apps/file-schema/network/network-element-network-settings