Can I recycle envelopes if they have plastic windows?
No you can't you must separate the two
Take the platic window off and recycle the paper envelope.
You must remove the plastic window if you want to recycle the envelope because they both go in to different recycling bins
YES. Most recycling facilities these days that have sorters (Waste Management, or any facility that collects recycling in one bin) will recycle paper through sieves, catching any plastic or waxes.