[Mimedefang] Mail exchangers at roaringpenguin.com

[Mark]

Perhaps one of the folks at roaringpenguin.com could shed some light on the
following. Examining my maillog, I found several of these entries (from my
own Milter):

Nov 19 22:40:23 asarian-host sendmail[9326]: hAJLeMcE009326: Milter:
from=<mimedefang-bounces at lists.roaringpenguin.com>, reject=550 5.7.1 We
accept no mail from dynamic/unresolvable IP space! [209.195.84.23] (via
dynablock.easynet.nl)

I was rather surprised at that. For starters, because I did not expect
roaringpenguin to be listed there:

23.84.195.209.dynablock.easynet.nl

And surprised, because I distinctly remember having whitelisted the mail
exchangers for roaringpenguin.com

--------------------------------------------------
asarian-host: {root} % nslookup -q=mx roaringpenguin.com
Server:  localhost
Address:  127.0.0.1

Name:    roaringpenguin.com
Address:  209.195.84.23

Non-authoritative answer:
roaringpenguin.com preference = 1, mail exchanger = www.roaringpenguin.com

Authoritative answers can be found from:
...
www.roaringpenguin.com  internet address = 216.191.236.23

And,

asarian-host: {root} % nslookup -q=mx lists.roaringpenguin.com
Server:  localhost
Address:  127.0.0.1

lists.roaringpenguin.com preference = 10, \
mail exchanger = lists.roaringpenguin.com
...
lists.roaringpenguin.com internet address = 216.191.236.23

--------------------------------------------------

So, my question is, why is roaringpenguin.com also sending mail directly
from its primary IP (209.195.84.23), and not using its mail exchangers? Or
am I missing something?

Also, it may be worthwhile to get yourselves delisted at
dynablock.easynet.nl. But since the mail exchangers of roaringpenguin.com
are not listed at dynablock.easynet.nl, if the former is fixed, I suppose
the latter no longer matters.

Thanks,

- Mark