My only recommendation is don't use your regular email server; use a different IP address. The company I was with had to prohibit employees from directly sending bulk mailings after the umpteenth time we got put on the RBLs from too much volume or complaints from customers who'd opted out with a different office or unit. It wasn't worth having our regular email interrupted.

We required our offices to let us scrub any mail list for opt-outs, include our centralized opt-out link in the message, and then use one of two approved sending methods: either a third party service (not too expensive, good delivery rate, and very good bounce reporting), or launch them from a server at our hosting provider, one that doesn't otherwise do email (almost free, but more RBL issues, and only so-so bounce reporting).

-jk