The installation of Tumbleweed Messaging Management System (MMS) 4.6 and earlier (formerly Worldtalk Worldsecure) creates a default account "sa" with no password.
https://exchange.xforce.ibmcloud.com/vulnerabilities/5072
http://www.securityfocus.com/bid/1562
http://thompson.tumbleweed.com/NewKB/bulletin/UPFiles/sa-official.htm
http://archives.neohapsis.com/archives/bugtraq/2000-08/0098.html