FundEasy automatically sends a confirmation email when someone sponsors a participant. It doesn't matter if they are registered publicly or from inside Ministry Sync. In the case of those paying online, it can serve as their tax receipt if you included your tax ID number in the Organization Information section in your Event Details. The language that accompanies that number can also be edited from there.
In the case of a pledge or a promise to mail a check, the confirmation provides instructions for payment and confirms for the sponsor that their sponsorship has been recorded. The payment instructions that appear on the confirmation email can be edited in the Donation & Payment tab in your FundEasy Preferences.