DirigoDev - 6:39 pm on Dec 29, 2012 (gmt 0)

Oh, you'll also want to be Sender Scored at some point. Not inexpensive at high volumes. You should use subdomains for sending different types of communication so that you can measure feedback on each IP address. Unless you are sending steady volume it is difficult to keep IPs warmed-up. Steady velocity is always better than spikes.