From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Sunshine Subject: Re: Eric Sunshine mail delivery failure Date: Sun, 23 Aug 2015 14:48:08 -0400 Message-ID: References: <20150811104056.16465.58131@localhost> <55CBA140.7050301@web.de> <20150813022545.30116.44787@localhost> <55D8C824.6000704@web.de> <55D993F8.4080506@web.de> <20150823171622.GA28700@zorg.kyriasis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: =?UTF-8?Q?Ren=C3=A9_Scharfe?= , Git List To: Elia Pinto X-From: git-owner@vger.kernel.org Sun Aug 23 20:48:16 2015 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ZTaJT-0003Im-Aj for gcvg-git-2@plane.gmane.org; Sun, 23 Aug 2015 20:48:15 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752985AbbHWSsK convert rfc822-to-quoted-printable (ORCPT ); Sun, 23 Aug 2015 14:48:10 -0400 Received: from mail-yk0-f180.google.com ([209.85.160.180]:33969 "EHLO mail-yk0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752430AbbHWSsJ convert rfc822-to-8bit (ORCPT ); Sun, 23 Aug 2015 14:48:09 -0400 Received: by ykdt205 with SMTP id t205so115854450ykd.1 for ; Sun, 23 Aug 2015 11:48:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type:content-transfer-encoding; bh=h6Ziw/1FWg6EDitcGfCS2X3hfrnG454eyD721X8/DGo=; b=qjCY43eqyf32/W+SHZAeq1xA1rYSVuDc1q4fxjSlt4oPDhpDVAVYhE36EoVqxbGc6x 4wSegsi4/7+yolMFvYUZCeTCR89dJ9MNKyogMivFNuFnxcslDjBCcYHcgTY+50ZsueV4 rfmxJWVbgvWdwIJ4b53nqT9a/Oc7k+OKkKv+U+aKGtdxbIvcrizt7mEUHPK0DptC4t0+ 5tXYbHTmOowvNSBZGKYnXJ52LnlFUnDjiLpiAWdwlXaOVo3Lxv4Saf8mgn/30SysaHEr xM7OLNrBQfF57qdcaRjLYyz1h/a0reQHyS2spIy6WeGhGEpY0rhQQUsZkJ+59iM1w0Ed 6BGA== X-Received: by 10.129.92.8 with SMTP id q8mr25246199ywb.163.1440355688423; Sun, 23 Aug 2015 11:48:08 -0700 (PDT) Received: by 10.37.208.78 with HTTP; Sun, 23 Aug 2015 11:48:08 -0700 (PDT) In-Reply-To: X-Google-Sender-Auth: 29nglOwgqpPtKFXnJINaOisr-2c Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Sun, Aug 23, 2015 at 2:36 PM, Elia Pinto w= rote: > Il 23/Ago/2015 20:26, "Eric Sunshine" ha sc= ritto: >> On Sun, Aug 23, 2015 at 1:16 PM, Johannes L=C3=B6thberg >> wrote: >> > Just an A record would be enough. The issue is that mail.sunshinec= o.com >> > has >> > neither an A nor an AAAA record, it is a CNAME to sunshineco.com, = which >> > is >> > invalid according to RFC2181. >> >> Interestingly, the default configuration for all domains managed by >> this service provider is for the mailhost to be a CNAME. While the >> restriction in section 10.3 of RFC2181 makes sense as a way to avoid >> extra "network burden", in practice, email services seem to be prett= y >> relaxed about it, and follow the CNAME indirection as needed. >> >> I suppose it's possible that web.de is being extra strict (although = it >> seems that such strictness would be painful for its users), or this >> could just be a temporary DNS lookup failure. It's hard to tell base= d >> upon the errors Ren=C3=A9 reported. >> >> I did change the CNAME to an A just in case, though who knows how lo= ng >> it will take for the change to propagate over to web.de's server. > Anyone can check Here https://dnschecker.org/#CNAME/Mail.sunshineco.c= om > It would fail with your change Interesting service; thanks for the pointer. However, since it's just querying a random set of DNS servers, it's not necessarily indicative of whether the change has actually propagated to the DNS server(s) answering web.de's mail server's queries. Local configuration (TTL's, etc.) on those servers or anywhere in between, as well as network conditions, could impact propagation to an unknown degree.