Unknown vulnerability in the Web calendaring component of Ipswitch IMail Server before 8.13 allows remote attackers to cause a denial of service (crash) via "specific content."
https://exchange.xforce.ibmcloud.com/vulnerabilities/17220
http://www.securityfocus.com/bid/11106
http://support.ipswitch.com/kb/IM-20040902-DM01.htm#FIXES