[I have one web page after filling the information I will get a password to the respective user maild id provided in the registration page...if I want continue next scenario that password is needed.... how can I follow... the steps... I have to take that password from database itself.. or what else...]

If it's a good database schema, the database will be encrypted so that won't work. You will have to query the mail server and retrieve the information from there instead.

telnet mailserver 110

user {mailUserName}

pass {mailUserPassword}

retr 1

// this assumes that there's only one message there dele 1