Sorry to say but that's the only option u have,using ActiveX Control and if it is blocked in your company then u cant use this control. Although in infopath 2010 contact selector can be used without using Activex Control. Further u have an option of making a list where u can give names of the people and their email ids. Prepare a secondary data connection to fill the dropdown with names and in VSTA u can write logic of sending a mail to an email id corresponding to selected name in dropdown while comparing it with the list..