If you have an Exchange package then it is possible to create forwarding type e-mail accounts. Forwarding type e-mail accounts do not have a mailbox to store e-mail but can forward any mails received to the supplied forwarded address. Forwarding type e-mail accounts are not able to send mails. This will have to be done from the Exchange account.
If you have added an Exchange account to a hosting package that has available e-mail accounts alloted, you would then be able to create a e-mail account with a mailbox in the Hosting package to receive, store and send e-mails.