What should I use for a forwarding only mail server?

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http://serverfault.com – I have a VPS running ubuntu 11.10 for a Django app, I want to be able to handle the email for one specific domain (already have the reverse lookup setup with the ISP for that domain), all I'm doing is forwarding email to different addresses, example [email protected] -> [email protected] , [email protected] -> [email protected] ... What should I use, and how do I set it up. I'm using Cherokee for the django app since I know someone's going to ask(I know nginx is supposed to do email, but I'm not switching). ()