Mail problems since moving to a new data center...

[8core]

We moved our servers to a new data center a couple of weeks ago. New set of static IP's. Ever since then, we have fought with email delivery, we seem to keep getting blocked. I think some of the IP's were on blacklists when we got them. We have spent a ton of time going around and around getting delisted in various place. Our RBL listings seem to be clean now, but we are still being blocked by some major providers.

Tried changing IP of our mail server. Created SPF records for the 30 or so domains we host. I have pored through the Postfix logs trying to see if there is a specific user that might be leaking spam, but no clear signs.

We have had no issues in the years leading up to a couple of weeks ago.

Can anyone provide some insight as to what I'm doing wrong here? The only substantial change I made was the SPF records, but that was done a week after the move in an effort to make our outgoing email more authoritative (I guess that's the word).

I've been a week now without being able to send to yahoo.com, sbcglobal.net, and now today, cox.net and comcast.com. I am on 20 or so of the FBL's, but have not received anything from any of them.

HELP! Customers will begin jumping ship shortly...

 

[8core]

How can I configure Postfix to send me a copy of every message (including content) incoming and outgoing?

In order to "prove" that our server isn't sending out offensive content is to examine the content.