[ale] Monitoring outgoing emails on Postfix, filtering incoming bounce back messages

[yahoo at jimpop.com (Jim Popovitch)]

On Mon, 2007-06-25 at 18:05 -0400, Jay Loden wrote:
> On a related topic, any better suggestions on how to filter out all
> these annoying bounce messages?

Here's how I do it:  Use 2 mail agents, each on their own IP, one for
acceptance (MX) and the other for outbound (MTA).  Then use iptables to
only allow inbound (and related) for the MX, and only outbound (and
related) for the MTA.  Postfix, as an MX, will then queue undeliverable
emails and you can periodically run postqueue to see what is held back.

-Jim P.