From what I understand (I've never gotten an RFE), and someone please correct me if I am wrong, you don't have to use the envelope they provide. You can use a larger full size envelope that will fit more evidence than a regular size one.
I also agree with MarieB, they are looking for things that have both you and your spouse showing the same address - copies of both Driver License/State ID with same address, if you already sent bank statements from joint account send more, same with joint credit card statements...if you already sent some send more. Send the rental agreement. Like I posted before, get tax transcripts from the IRS (these are better proof than W2s and copies of tax return).
If you have any cards or letters sent to both of you at the same address from friends/family or things like that...this is secondary evidence but might help.
sarah&rob got a reaction from MarieB15 in I-751 February 2011 Filers