Buffer overflow in Pegasus mail client 4.01 and earlier allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via long (1) To or (2) From headers.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2002-1063
http://www.securityfocus.com/bid/5302
http://www.iss.net/security_center/static/9673.php
http://archives.neohapsis.com/archives/bugtraq/2002-07/0277.html