Microsoft Outlook 2000, 2002, and 2003 allows user-assisted remote attackers to cause a denial of service (memory exhaustion and interrupted mail recovery) via malformed e-mail header information, possibly related to (1) long subject lines or (2) large numbers of recipients in To or CC headers.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A122
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2007/ms07-003
http://www.vupen.com/english/advisories/2007/0104
http://www.us-cert.gov/cas/techalerts/TA07-009A.html
http://www.securityfocus.com/bid/21937
http://www.securityfocus.com/archive/1/457274/100/0/threaded
http://www.kb.cert.org/vuls/id/617436
http://securitytracker.com/id?1017488
http://secunia.com/advisories/23674
http://osvdb.org/ref/24/24081-outlook1.txt