A system and method for processing messages being composed by a user of a computing device (e.g. a mobile device). Embodiments are described in which the performance of certain tasks is initiated before a direction is received from a user to send a message being composed by the user. This may involve, for example, ''pre-fetching'' security-related data that will be required in order to send a message that is in the process of being composed by the user securely. Such data may comprise security policy data, certificate data, and/or certificate status data, for example.