回複：從收到需要RFE的email到真正收到mail一般要多久?

I received email said 08/22 they mailed out RFE for my LD, but waited till 09/02 and received the letter, but I found that they actually mailed it on 08/26 ( as letter dated). So it's kind hard to tell, if it's on road already, it usually take 7 days to arrive if it was actually mailed.