Sendamil

[Joy Methew]

hello all
              i am using sendmail server for incoming and outgoing mails.
              this is a public mail server like gmail.
              you all the guys know that if  any client wann use my mail
server for outgoing mails
             it should be realy on my mail server.
             but we have lot of clients and it`s not possible we give every
and each client entry in our mail server.
             can we make apache and sendmail combination???

            how we can solve this problem???