Don't be anxious about sending reminder letters. At the sharp end, people simply forget to respond and we all know how that goes! Others intend to reply later or are not quite sure yet what their response will be. It is fine to send a polite reminder letter asking people to return their response form. At our end, as those sending the reminders, remember that the same purpose that inspired the initial clergy letter still applies. You are inviting people to be partners in the church’s mission, so don't let it become a matter of anxiety.