Integer overflow in inetcomm.dll in Microsoft Outlook Express 5.5 SP2, 6, and 6 SP1; Windows Live Mail on Windows XP SP2 and SP3, Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, and R2, and Windows 7; and Windows Mail on Windows Vista SP1 and SP2, Windows Server 2008 Gold, SP2, and R2, and Windows 7 allows remote e-mail servers and man-in-the-middle attackers to execute arbitrary code via a crafted (1) POP3 or (2) IMAP response, as demonstrated by a certain +OK response on TCP port 110, aka "Outlook Express and Windows Mail Integer Overflow Vulnerability."
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6734
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2010/ms10-030