1. A method, comprising: receiving, by an electronic mobile device, a managed personal information management (PIM) application from an application server during a first communication, the managed PIM application being constructed to operate in accordance with a set of one or more policy files, wherein the one or more policy files define access controls that are enforced, by a mobile device management system on the electronic mobile device, against a plurality of different managed applications executing on the electronic mobile device; receiving, by the electronic mobile device, the set of one or more policy files from the application server during a second communication which is different than the first communication, the set of one or more policy files being stored on the electronic mobile device separately from the managed PIM application; running, by a processor, the managed PIM application on the electronic mobile device, the managed PIM application operating in accordance with the set of one or more policy files, wherein one of the policy files alters a message processing functionality of the managed PIM application on the electronic mobile device by defining one or more of the plurality of managed applications with which data sharing is permitted by the managed PIM application, and restricting the managed PIM application from sharing data with any application not permitted by the one or more policy files; communicating, by the managed PIM application and based on the set of one or more policy files, with an enterprise resource via one or more application tunnels, wherein the managed PIM application, based on the set of one or more policy files, selectively employs caching and/or a compression technique within the one or more application tunnels; and selectively providing a single sign-on (SSO) credential, by the managed PIM application in accordance with the set of one or more policy files, to authenticate a user and access a document stored in a secure document container of the mobile device, wherein the managed PIM application encrypts data stored in the secure document container, wherein the set of one or more policy files permit use of the SSO credential with the managed PIM application and block use of the SSO credential with a different application.