<p>First, some background info:
One of my two recs was listed as "not received" online for several weeks, but since my teacher assured me that he'd sent it, I kept on waiting for it to appear. Ultimately it got lost in the mail or something, because the status on Columbia's website never changed. But by that time the admissions committee was already meeting, and so re-sending it wouldn't have helped me. CC was already a major reach for me, and so I resigned myself to the fact that I'd be getting rejected. Apparently I sold myself short, since I managed to get on the waitlist.</p>
<p>So how likely is it that this one missing piece of my application is what led to me being waitlisted? And more importantly, would it help me at all if I got my teacher to resend them his rec?</p>