TIBCO Spotfire Automation Services job Send email task fails with "System.Security.Authentication.AuthenticationException" exception.

TIBCO Spotfire Automation Services job Send email task fails with "System.Security.Authentication.AuthenticationException" exception.

TIBCO Spotfire Automation services job(Send email task) may fail with the following error:

FAILED: Task X 'Send Email' failed with: Failed to send email using SMTP server 'xxxxxxxxx' from 'yyyyyyyyyyyyyy' to 'zzzzzzzzzzzzzzzzzzzzzz'.
Reason: System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.
   at System.Net.Security.SslState.StartSendAuthResetSignal(ProtocolToken message, AsyncProtocolRequest asyncRequest, Exception exception)
   at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncReque


  This happens if useTls setting in Spotfire.Dxp.Worker.Automation.config file is Set to "True" as below to use Transport Layer Security (TLS) when connecting to the SMTP server. 

<smtp port="25" useTls="true" timeoutSeconds="100">
      <authentication useWindowsDefaultCredentials="false" username="" password="" />
      <certificates useCertificates="false" storeLocation="LocalMachine" storeName="My" serialNumber="" />
    </smtp>

By default this is false. To resolve the issue, change the useTls setting  to "False" as below in  Spotfire.Dxp.Worker.Automation.config file and import the Automation Services configuration.

<smtp port="25" useTls="false" timeoutSeconds="100">
      <authentication useWindowsDefaultCredentials="false" username="" password="" />
      <certificates useCertificates="false" storeLocation="LocalMachine" storeName="My" serialNumber="" />
    </smtp>

Doc: Spotfire.Dxp.Worker.Automation.config file

• https://docs.tibco.com/pub/spotfire_server/10.7.0/doc/html/TIB_sfire_server_tsas_admin_help/GUID-996114A8-DD2A-4506-B798-1D8404AB1A04.html