Message No.XS829 Internal error: CL_SMTP_RESPONSE ESMTP error code is not known. 505 505 Authentication required.
This problem is related to the mail server definitions. Using Exchange, the mail server is set to accept authenticated connections only.
The SMTP client does not use authentication and this is why it is rejected by your exchange server.
To avoid this error message, in the Exchange Server / Connections / IMS properties page, there's a tab called Connections with a property called "accept connections".
It is set to accept authenticated connections.
On that tab - click on the "specify by host" button and create a specific definition for your Controller/Center node IP to be accepted without authentication.
The scenario is for MS Exchange. If you are using Sendmail or any other mail server you will have to contact your mail adminstrator for instructions on
how to setup anomymous connections from SAPConnect.