I volunteer in my spare time.  Do you like volunteering? 
Absolutely, I have volunteered a few times at food banks and animal shelters.
Did you help with storing the food collected? Or did you sort the food? 
We filled packages with a variety of items, ranging from chips to fruits and canned veggies.
Were you a participant of the Stamp out Hunger Food Drive? 
Not sure what that is, but it sounds like something I'd like to participate in.
It is a charitable initiative started by the National Association of Letter Carriers. 
Are letter carriers like postmen?