Конфигурация делается с помощью config параметров:
SMTPFromAddr An address used for sending mail from.
SMTPFromName A name used for sending mail.
SMTPPort TCP port for SMTP server.
SMTPRetryCount Number of retries for sending mail.
SMTPServer An SMTP server used for sending mail.
http://wiki.netxms.org/wiki/Server_Configuration_Variables
SMTPFromAddr An address used for sending mail from.
SMTPFromName A name used for sending mail.
SMTPPort TCP port for SMTP server.
SMTPRetryCount Number of retries for sending mail.
SMTPServer An SMTP server used for sending mail.
http://wiki.netxms.org/wiki/Server_Configuration_Variables