This is a sample message that you could use to send to a member of your group.
Dear Freegle Member,
I'm sorry I can't approve your message on Freegle today. I know that 'swapping' an item often seems like a good, environmentally friendly idea - but Freegle is just for giving things away free to keep them from ending up in landfill. You could of course place a wanted ad for the item you need.
If you would like to reword your post as a straight offer, you are welcome to repost it.
Kind Regards $myname $groupname Volunteer $owneremail