> That's fine, but this is neither here, nor there. If the DNS lookup > failed, you don't know whether the domain has MX records, or not. There is a difference between a failed DNS-lookup and an empty result. I'm pretty sure, in this case the DNS lookup did not fail, but return an empty result:
$ host -t mx gabelgelb.xyz gabelgelb.xyz has no MX record An example for a failed DNS-lookup (I disabled the network adapter for this) would be: $ host -t mx gabelgelb.xyz ;; connection timed out; trying next origin ;; connection timed out; no servers could be reached I can also reproduce this with my own (sub-)domain test.con-data.net: $ host -t txt test.con-data.net test.con-data.net descriptive text "v=spf1 a mx -all" $ host -t mx test.con-data.net test.con-data.net has no MX record $ host -t a test.con-data.net test.con-data.net has address 192.168.0.1 $ telnet 193.164.131.61 25 Trying 193.164.131.61... Connected to 193.164.131.61. Escape character is '^]'. 220 mail.con-data.net ESMTP ehlo test.con-data.net 250-mail.con-data.net Ok. 250-AUTH LOGIN PLAIN 250-STARTTLS 250-XVERP=Courier 250-XEXDATA 250-XSECURITY=NONE,STARTTLS 250-PIPELINING 250-8BITMIME 250-SIZE 250 DSN mail from: <i...@test.con-data.net> 250 Ok. rcpt to: <d...@didi-site.de> 250 Ok. data 354 Ok. From: <i...@test.con-data.net> To: <d...@didi-site.de> Subject: test test . 250 Ok. 0000000056D99488.000076E6 quit 221 Bye. Connection closed by foreign host. > Delivered-To: d...@didi-site.de > Return-Path: <i...@test.con-data.net> > Received: from test.con-data.net ([::ffff:79.203.85.47]) > by mail.con-data.net with ESMTP; Fri, 04 Mar 2016 14:58:05 +0100 > id 000000006006DF8C.0000000056D99488.000076E6 > Authentication-Results: mail.con-data.net; > dnswl=pass dns.zone=pbl.spamhaus.org > policy.ip=127.0.0.10 > policy.txt="https://www.spamhaus.org/query/ip/79.203.85.47"; > Received-SPF: error (DNS MX lookup failed.?) > SPF=HELO; > sender=test.con-data.net; > remoteip=::ffff:79.203.85.47; > remotehost=; > helo=test.con-data.net; > receiver=mail.con-data.net; > Received-SPF: error (DNS MX lookup failed.?) > SPF=MAILFROM; > sender=i...@test.con-data.net; > remoteip=::ffff:79.203.85.47; > remotehost=; > helo=test.con-data.net; > receiver=mail.con-data.net; > From: i...@test.con-data.net > To: d...@didi-site.de > Subject: test > > test ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=272487151&iu=/4140 _______________________________________________ courier-users mailing list courier-users@lists.sourceforge.net Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
