Buffer overflow in ISMail 1.4.3 and earlier allow remote attackers to execute arbitrary code via long domain names in (1) MAIL FROM or (2) RCPT TO fields.
https://exchange.xforce.ibmcloud.com/vulnerabilities/11432
https://euvd.enisa.europa.eu/vulnerability/EUVD-2003-1372
http://www.securityfocus.com/bid/6972