Unable to send emails to a list that I'm subscribed to

I have an email address at my own domain (foo@bar.com), and I have it forwarding to my GMail account, and I use the GMail send as feature to send emails as foo@bar.com from my GMail account. Other mailing lists that restrict sending to subscribers only have no problem with this, but Xircles rejects my emails, here's an example error with the headers from the email I sent:

Hi. This is the qmail-send program at mail.codehaus.org.
I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.

<user@jackson.codehaus.org>:
Sorry, only subscribers may post. If you are a subscriber, please forward this message to user-owner@jackson.codehaus.org to get your new address included. (#5.7.2)

— Below this line is a copy of the message.

Return-Path: <myaccount@gmail.com>
MIME-Version: 1.0
Sender: myaccount@gmail.com
Received: by 10.204.101.211 with HTTP; Wed, 7 Dec 2011 08:54:37 -0800 (PST)
From: James Roper <foo@bar.com>
Date: Wed, 7 Dec 2011 17:54:37 +0100
X-Google-Sender-Auth: XXXXX
Message-ID: <CAPf2pwXBsxW+dY8PDi1wtA16m57CG7PEf9DkUwt-sNNjYHReFg@mail.gmail.com>
Subject: Some Subject
To: user@jackson.codehaus.org

I think Xircles should be honouring the From mime header, not just Sender.