identify the mail server for mail command

Hi ,
I am new to unix , i am using the mail and mailx command to send the mail .How come i will know the my mail command using which server as mail box..

Please help me ..

Thanks in advance

If you r un solairs, go /etc/mail
ter u can find sendmail.cf

more /etc/mail/sendmail.cf

ter u can find the line of relay host
Under that ur mail server should be configured as
mailserver.DS