Apple has launched a free hosted business email service, Apple @ Work, aimed at challenging Google and Microsoft in the enterprise email and calendar market. The service is designed to streamline operations and is available for up to 500 users. Users can use their own custom domain name or purchase a new one directly from Apple. The new service also includes essential business scheduling tools like calendar delegation and a built-in company directory. Users get 5GB of free iCloud storage, but can upgrade users to tiers up to 2TB starting at just $0.99 per user per month. The technical aspect of this announcement is that Apple is supporting open standards for email, so there is no requirement for businesses to swap out their fleets if they have some users on Android or Windows.