When sending your support materials, a single envelope containing those documents is strongly recommended. When you send more than one, this not only delays your application in the review process, but there is a chance that your application will remain in-complete and not be accepted or reviewed.

Ideally, the support material would be laid flat, with no folds or staples. Of course letters of recommendation and transcripts would be in sealed envelops per standard application format. We recommend this because our department received many applications which have to be opened, un-folded and un-stapled. This service would be appreciated.