Same here, I don't like having mail daemons running on 30+ virtual machines, but I do it anyway, with postfix similar to Nate. I'm obsessive-compulsive when it comes to minimizing the footprint of a virtual machine, but I've given up on this one. An advantage to having outbound mail handled by a local daemon is the queuing of failures. When your mail server or network is temporarily down, you don't want to lose messages.
Yeah, that is my reasoning but your justification is good.
Thanks guys! jlc