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