An email hosting service is an Internet hosting service that operates email servers. 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 or Postfix. Hosting providers can manage a user's own domain name, including any email authentication scheme that the domain owner wishes to enforce in order to convey the meaning that using a specific domain name identifies and qualifies email senders. Most email hosting providers offer advanced premium email solutions hosted on dedicated custom email platforms. The technology and offerings of different email hosting providers can therefore vary with different needs. Email offered by most webhosting companies is usually more basic standardized POP3-based email and webmail based on open source webmail applications like Horde, RoundCube or SquirrelMail. Almost all web hosting providers offer standard email hosting.