The IMAP service (MEIMAPS.exe) in MailEnable Professional Edition and Enterprise Edition 3.13 and earlier allows remote attackers to cause a denial of service (crash) via (1) SEARCH and (2) APPEND commands without required arguments, which triggers a NULL pointer dereference.
https://exchange.xforce.ibmcloud.com/vulnerabilities/41059
https://euvd.enisa.europa.eu/vulnerability/EUVD-2008-1285
http://www.vupen.com/english/advisories/2008/0799/references
http://www.securitytracker.com/id?1019565
http://www.securityfocus.com/bid/28145
http://www.securityfocus.com/archive/1/489270/100/0/threaded
http://securityreason.com/securityalert/3724