Already had an additional rec letter sent, but teachers sent in three accidentally

<p>I know Stanford only asks for two teacher letters and one optional additional, so that’s what I had sent initially. I had a third teacher write a letter for a different college, but she automatically sent hers to Stanford as well, so now I have four letters submitted…will they just discard one, or should I email them about it?? Especially because the third teacher letter and my additional letter are both about debate. Will this hurt my application?</p>