1. A method to manage an email filter associated with a client computing machine, the method comprising: collecting information as a user navigates to and interacts with external websites; applying one or more rule-based criteria to the collected information to determine a characterization to be applied to an initiator of an email message, the characterization being that the initiator is trusted; providing the characterization to the email filter to facilitate an email filter operation with respect to a subsequent email message received from the initiator; and dynamically and in an automated manner as a given initiator is determined to be trusted, applying the rule-based criteria to the collected information and, in response, generating a filter update command that instructs the email filter to modify a preexisting email filter entry, to thereby improve an email system associated with the client computing machine; wherein the collecting, applying and providing steps are carried out in software executing on a set of one or more computing devices.