This attitude drives me nuts. Why would anyone want a staff of sysadmins? You're almost certainly buying (at a high capital outlay) the B-team when you can rent the A-team for next to nothing.
There's nothing magical about your "private network". These days corporate networks are chock full of holes and ripe with hypocritical security priorities.
Use Google apps for business ($50/year/user). Hire one of the many companies that archive Google Apps data.
It is total folly to think that you'll buy better security by paying for your own infrastructure and a small army to run it. That's like claiming the only safe automobile is one that you and your friends build.
As I said in my comment, this is never going to fly for any company past a certain size. There is just too much confidential and legally sensitive stuff going through your email on a daily basis. Especially if you want to go public at some point (or even be acquired).
As a lawyer, I respectfully scoff at this response. The exchange servers running the biggest companies in the world are sourced to third party providers. I love how people will put their "legally sensitive" stuff in the hands of a $60K/year sysadmin, but not in the hands of a multi-billion dollar infrastructure operations specialist that also happens to manage the world's best index of Internet content. I really struggle to follow the logic.
There's nothing magical about your "private network". These days corporate networks are chock full of holes and ripe with hypocritical security priorities.
Use Google apps for business ($50/year/user). Hire one of the many companies that archive Google Apps data.
It is total folly to think that you'll buy better security by paying for your own infrastructure and a small army to run it. That's like claiming the only safe automobile is one that you and your friends build.