Listmasters against IPv6?

Received: from [2001:838:37f:20:2c0:dfff:fef2:8eae] (helo=rock.grep.be)
        by folk.grep.be with esmtp (Exim 3.35 1 (Debian))
        id 1At6dk-00064i-00; Tue, 17 Feb 2004 15:56:00 +0100
[...]
X-Debian-Message: suspicious IP address in Received: line - could be one of cyberpromo's tricks "[2001"
Resent-Message-ID: <iosN5C.A.s_B.g9iMAB@murphy>
Resent-From: debian-l10n-dutch@lists.debian.org
X-Mailing-List: <debian-l10n-dutch@lists.debian.org> archive/latest/1454

Hmmm?