1POP Account Sharing by 5 user

I got a problem. We have one pop account leebamo@bol-online.com. Here bol-online.com is my ISP Domain. We check mail From Lan Work stations Using winproxy. But we can not Check mail at a time. we get pop lock error. Is ther any Server that can download all the mail to our office server at a time then we will download the mail from our office server at time.Please Advice me