Buffer overflow in the S/MIME Parsing capability in Microsoft Outlook Express 5.5 and 6.0 allows remote attackers to execute arbitrary code via a digitally signed email with a long "From" address, which triggers the overflow when the user views or previews the message.
https://docs.microsoft.com/en-us/security-updates/securitybulletins/2002/ms02-058
http://www.securityfocus.com/bid/5944
http://www.iss.net/security_center/static/10338.php
http://marc.info/?l=ntbugtraq&m=103429681123297&w=2