SORBS lists mx2.freebsd.org as open relay

[Chris Shenton]

I was adding RBL blacklisting to my qmail setup, with rblsmtpd using
some blacklists which a couple folks on inet-access suggested.  I
noticed it logging connections from mx2.freebsd.org as being in SORBS:

rblsmtpd: 216.136.204.119 pid 45632: 451 Open Relay See: http://www.dnsbl.sorbs.net/cgi-bin/lookup?IP=216.136.204.119

That web page indicates port 25 is an open relay, failing a test
on April 7 2004 01:46:38 GMT, relaying from relays at sorbs.net, to
spamtest at sorbs.net. 

I manually confirmed their test, it appears as if it's a relay. 
This seems surprising since I know you guys have clue.

When I test using some of my own addresses, it says

  Recipient address rejected: Relay access denied

So is mx2.freebsd.or intentionally relaying from/to SORBS? On purpose?
To fool it into thinking it's a relay when it's not? Any other ideas?

I'd like to use some semi-reputable RBLs but can't afford to block
freebsd mail. 

Thanks.