Have a look in the rbEnotify log file on the RBS Server.

WSCK: ERROR 11004 - Valid name, no data record of requested type...

followed by a SendEmailNotification message including the SMTP server's name.

Winsock Errors are Microsoft Windows Sockets (TCP) errors, not RBS software errors, and are not directly related to RBS software.

This specific Winsock error implies some types of Names Resolution issues within the network environment. RBS software does not directly perform any type of Name Resolution, it simply asks the Operating System to perform all Name Resolution, and this error is being returned by the Operating System to the software. Therefore, if the SMTP Server Name is being entered by its Host Name or FQDN (fully qualified domain name), try using the IP address instead. This may resolve the issue.

Also make sure the SMTP server name is spelled correctly.