Email to Stanford Faculty ; Do they reply?

[Bohme88]

I am preparing to apply to Stanford's Bio sciences and Earth System Science for PhD program. Did people who got admitted talk to the professors first before they submitted the applications? They must get dozens of emails from desperate students every day. Do Stanford professors even respond to the emails even when the candidate has the possibility of getting in ? Do they wait the admission committee sieve the applicants first and talk to those who get shortlisted or admitted?  Let me know if anyone of you have luck getting response back from Stanford professors?