Multiple buffer overflows in MERCUR Messaging 2005 before Service Pack 4 allow remote attackers to cause a denial of service (crash) via (1) "long command lines at port 32000" and (2) certain name service queries that are not properly handled by the SMTP service.
https://exchange.xforce.ibmcloud.com/vulnerabilities/27231
http://www.vupen.com/english/advisories/2006/2354
http://www.securityfocus.com/bid/18462