IMAP service in MailEnable Professional Edition before 1.72 allows remote attackers to cause a denial of service (service crash) via unspecified vectors involving the EXAMINE command.
https://exchange.xforce.ibmcloud.com/vulnerabilities/24424
http://www.vupen.com/english/advisories/2006/0397
http://www.securityfocus.com/bid/16457
http://www.mailenable.com/professionalhistory.asp