Polymailers & padded envelopes which are suitable for reuse are accepted by some small businesses owners. Offer it for free online or drop it off with Package Pals.
It can be logistically difficult for small business owners to collect used packaging in small batches. Saving up large quantities of used packaging makes it more worth it for small businesses to collect from you.
This kind of plastic cannot be recycled.
There is far more supply of used polymailers than demand so if it is not convenient for you to drop off at a donation location, just put them in the trash.
Do NOT, under any circumstances, attempt to recycle these! This kind of flat plastic can look a lot like paper. When it is misidentified as paper in the sorting plants, it contaminates paper recycling making paper recycling rates much worse.
This is bad stuff. Reuse or throw out.