the first time someone sendsus an email they receive the out of office reply. However if they continue to send emails they will not receive the reply again. our email is only sending the autoreply to each email once. is there a way to configure exchange to send reply everytime someone sends an email or should this be done at the client end?

If you really want a reply send out each time, users can create a rule in outlook that replies to each mail.Beware though this can cause mail bouncing between servers.