source: http://www.securityfocus.com/bid/813/info

The ZetaMail mail server will crash if a username/password pair longer than 3500 characters is supplied by the client. 

19636-1.exe - binary for windows
19636-2.zip - source for windows
19636-3.tgz - source for linux 

http://www.exploit-db.com/sploits/19636-1.exe

http://www.exploit-db.com/sploits/19636-2.zip

http://www.exploit-db.com/sploits/19636-3.tgz