Single Exchange Server/Multiple domains

Does anyone know if it is possible to allow several email domains and accounts, (userA@xxx.com, userB@yyy.com, userC@zzz.com), to run off a single exchange server? We have several registered domains and would like to set up unique email addresses for individuals depending on the domain they reside.

NOTE: the domains are not subdomains of a parent (child.parent.com)but are totally unique domains.

Any input would be appreciated!

Thanks in advance.