The SMTP server in Apache Java Mail Enterprise Server (aka Apache James) 2.2.0 allows remote attackers to cause a denial of service (CPU consumption) via a long argument to the MAIL command.
https://exchange.xforce.ibmcloud.com/vulnerabilities/26786
https://euvd.enisa.europa.eu/vulnerability/EUVD-2006-2803
http://www.securityfocus.com/bid/18138
http://www.securityfocus.com/archive/1/435278/100/0/threaded