Envelopes Paper Recycling Remove Plastic Windows The little plastic windows on envelopes cannot be recycled. Although modern recycling systems can filter out these windows, it’s still best to cut out the windows before recycling envelopes. Ways to Reduce Get Off Mailing Lists Junk mail generates a lot of waste on a weekly basis. You can reduce the amount of junk mail you receive by signing up with TrustedID Mail Preference Service. Ways to Reuse Use Envelopes More Than Once As much as possible, try to use envelopes more than once before disposing of them. You can cover old addresses with labels or by crossing them out.