I would suggest that if the organization is one that you find worthy, honorable or whatever, I suggest you not stick them with the postage. I get requests from good Christian ministries and I would not want to hurt them with the postage.
what about liberal churches?
nah, better to just not donate to orgs at all
if you know a family in need of help until the next EBT day, you can choose to help them witn 0% overhead
But what point is a peevish, misdirected, ill-advised gesture if it doesn't hurt them with the postage?