550-5.7.1 refusing mtr(8) output; other excessive bounces

This has happened to me several times recently; has never happened until a couple of weeks ago.

From the web-interface, Cc an alias

on my server, which expands to, amongst other things, my email address; a bounce is immediately received in the thread (apparently, gmail doesn't reject the bounces from the very same server from which some messages are rejected). Most likely cause: too many domain names from the mtr(8) output in the message.

Same for sending a similar message directly from my own server, directly to my address, being in the Cc field: a bounce is received within my own server, no message is received at gmail. The bounce from such an experience is at the end of this message.

I consider this a major outage: how many other valid semi-automated emails addressed to myself have been unfairly rejected by gmail on the SMTP level recently?

I also now know why my address has been unsubscribed from several mailing lists over this summer, citing excessive bouncing. My own mailserver wasn't even involved:

Received: by with SMTP id q6csp13073ldq;
        Tue, 10 Sep 2013 03:43:00 -0700 (PDT)
X-Received: by with SMTP id d11mr18914232bkk.3.1378809779724;
        Tue, 10 Sep 2013 03:42:59 -0700 (PDT)
Return-Path: <>
Received: from ( [])
        by with ESMTPS id zk7si1773373bkb.190.1969.
        (version=TLSv1 cipher=RC4-SHA bits=128/128);
        Tue, 10 Sep 2013 03:42:59 -0700 (PDT)
Received-SPF: neutral ( is neither permitted nor denied by best guess record for domain of client-ip=;
       spf=neutral ( is neither permitted nor denied by best guess record for domain of
Received: from localhost ([::1]
  by with esmtp (Exim 4.80.1)
  id 1VJLPJ-0001fB-QJ
  for; Tue, 10 Sep 2013 12:42:59 +0200
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit