EmailCrk是一个基于POP3协议的自动登录机。一般对于UNIX机器来说，其每一个用户都有相应的Email帐号，而且Email帐号的密码和登录密码是一样的。这样，如果能够得到用户的Email帐号密码，就可以得到他的登录密码。EmailCrk就是利用POP3协议的功能，对可能的用户密码进行登录试验，从而获得用户的密码。-EmailCrk is based on the POP3 agreement automatically
registering machine. Generally said regarding the UNIX machine that,
its each users all have the corresponding Email account number,
moreover the Email account number password and registers the password
is same. Thus, if can obtain the user the Email account number
password, may obtain him to register the password. EmailCrk is uses
the POP3 agreement the function, to carry on to the possible user
password registers the experiment, thus obtains the user the password.