Clickz: Dedicated vs shared IPs

When you are looking to get a new ESP and/or considering taking it in house, deliverability is the key.
If you tell an ESP that you are considering going in house the frist thing they will say iss “oh no, you don’t want to do that, deliverability is a nightmare to manage, let us do it”. Normally they are right!

If you’re a big sender and you have not got complete double optin for every email you send someone, ie: every email they get from you they have specifically requested; you could find your sending IPs dead in 6 weeks, and that’s even if they had a good rep to start with. If you just buy new IPs they’ll have no rep at all, so like a credit rating they’ll be useless.

The legend of Jeanne Jennings, writes about this is detail for Clickz on Jul 27, 2009 in “E-Mail: Evaluating Dedicated vs. Shared IP Addresses“.
As with everything Jeanne (and Mark Brownlow) writes about email, it’s more likely than not to be bang on the money.