回複：Submitting 140 RFE materials

when you receive your rfe, USCIS will provide you a envelop with a mailing address on it,just like a regular one, when you submit your additional evidence, you can either use their envelop if you have just a few pages of materials, or use your own big envelop if you have piles of documents to send in, but remember to put their envelop on the top of your documents.