The ActiveSync option is enabled on a per-account basis and can be inherited, as any other regular option is, from either the domain level or through the means of an Account Class object. Thus, the other inheritance state (explicitly set) is also supported and can be used if a limited number of accounts are set to use this feature. The number of accounts that have access to this feature is limited through the licensing information. The trial and office editions of the product do not offer this feature and, in this instance, it cannot be activated.

In order to enable the ActiveSync option at the account level, an administrative account, which has sufficient privileges to change this setting, must log into the web administration interface and access the “Quotas and Restrictions” page for that account. On this page, in the “Webmail Restrictions” section, the following options are available:

The “Enable ActiveSync” check box activates the availability of this feature. The other sub-options specify which functionalities of the feature are accessible to the respective account.

Email. Specifies access to email pushing through the ActiveSync protocol. This functionality enables the handset to synchronize the local mailbox contents with the server-side mailbox and maintain their consistency.
Contact. Specifies access to the contact address book stored on the server and the possibility to synchronize the contacts stored on the handset with the ones stored on the server.
PIM. Specifies access to the contact calendar and task information stored on the server. Using this functionality, the user can update appointment and task completion levels (as well as create and delete objects) using the mobile device.