Is Google boycotting itself?

(Yeah, that’s somewhat provocatively tongue-in-cheek…)
OK, maybe someone can explain this to me: I’ve been trying to post to a mailing list for the past few days, after a long time during which posting was no problem. It now looks like the mail is getting stuck — and it’s because gmail can’t verify that mail is valid when coming from, er, gmail!
(At least from what I can tell, googlemail and gmail are the same thing…)

Here’s the header of one of the messages:

X-Gmail-Received: 4146ee044f4434916924e4a460839cdc8df4eb23
Delivered-To: josephDOTzitt@gmail.com
Received: by 10.70.46.14 with SMTP id t14cs494979wxt;
Tue, 3 Oct 2006 18:03:59 -0700 (PDT)
Received: by 10.70.91.11 with SMTP id o11mr299wxb;
Tue, 03 Oct 2006 18:03:59 -0700 (PDT)
Return-Path: <>
Received: by 10.70.91.11 with SMTP id o11mr1111wxb;
Tue, 03 Oct 2006 18:03:59 -0700 (PDT)
From: Mail Delivery Subsystem
To: josephDOTzitt@gmail.com
Subject: Delivery Status Notification (Delay)
Date: Tue, 03 Oct 2006 18:03:59 -0700 (PDT)

This is an automatically generated Delivery Status Notification

THIS IS A WARNING MESSAGE ONLY.

YOU DO NOT NEED TO RESEND YOUR MESSAGE.

Delivery to the following recipient has been delayed:

Rosegarden-user@lists.sourceforge.net

Message will be retried for 2 more day(s)

Technical details of temporary failure:
TEMP_FAILURE: SMTP Error (state 9): 451-Could not complete sender verify callout
451-Could not complete sender verify callout for .
451-The mail server(s) for the domain may be temporarily unreachable, or
451-they may be permanently unreachable from this server. In the latter case,
451-you need to change the address or create an MX record for its domain
451-if it is supposed to be generally accessible from the Internet.
451 Talk to your mail administrator for details.

—– Message header follows —–

Received: by 10.70.91.11 with SMTP id o11mr7646352wxb;
Mon, 02 Oct 2006 16:11:31 -0700 (PDT)
Received: by 10.70.46.14 with HTTP; Mon, 2 Oct 2006 16:11:31 -0700 (PDT)
Message-ID:
Date: Mon, 2 Oct 2006 16:11:31 -0700
From: “Joseph Zitt”
To: Rosegarden-user@lists.sourceforge.net
Subject: FluidSynth-DSSI interface
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
----- Message body suppressed -----

(I’ve obscured my email address a little, but the rest is verbatim.)

I’ve dug through their labyrinthine help system with finding anything, down to and including any way to reach a human. Odds are good that at least one person at Google reads this blog.

So, er, any clues anyone?