Email hosting services usually offer premium email as opposed to advertisement-supported free email or free webmail. Email hosting services thus differ from typical end-user email providers such as webmail sites. They cater mostly to demanding email users and small and medium-sized (SME) businesses, while larger enterprises usually run their own email hosting services on their own equipment using software such as Microsoft Exchange Server, IceWarp or Postfix. Hosting providers can manage a user’s own domain name, including any email authentication scheme that the domain owner wishes to enforce to convey the meaning that using a specific domain name identifies and qualifies email senders.