Vitesse CRM is the email marketing software that allows advanced relational e-marketing features:

The search of users to send the message to could be run by using also company data, like sales data, mixed with users declared preferences. Confidential data could be used just for the search and then deleted.

You can show each user the data that belongs to her/him, like the gained points in a fidelity program or the tracking of an order or a task.

You could collect information from users, their telephone number, their complete address,....a real market research could be done and have the collected information available for future use.