mail delivery fail with message "DNS server returned answer with no data"

[Gijs Molenaar]

Summary:
Sometimes gmail users can't mail to mailinglist on the host
'lists.pythonic.nl'; they get the error 'DNS Error: DNS server
returned answer with no data'.

Details:
I'm maintaining a mailinglist on a server. Sometimes some gmail users
get this error while posting to the mailinglists:

Technical details of permanent failure:
DNS Error: DNS server returned answer with no data

The DNS server is serving normally, no extreme load on system or
network or whatsoever. Also no strange DNS configuration, just a
simple A record to the IP. It doesn't happen all the time. Only gmail
users have this problem. The same happend 2 months ago for 1 day and
the problems disappeared automagically. It happened again a couple
of days ago, now it is happening again.

Please let me know if you know what is the problem, or if you have a
suggestion where to look. Also I don't really know where to look for
google technical support, if somebody has a hint for that please let
me know also. Your answer is appreciated.


Thanks,

- gijs

[Zack (Doc)]

Gijs,

The first lookup done is not for the A record but for the MX record.  You didn't indicate a typical address a user uses when they send to your list, but here's some of the results I got which are suspicious to me and MIGHT be related to your problem.  If I look up the MX for pythonic.nl I get:

pythonic.nl     MX preference = 10, mail exchanger = mail.pythonic.nl

Then I lookup up mail.pythonic.nl and I get:

mail.pythonic.nl        canonical name = bach.pythonic.nl

bach.pythonic.nl        internet address = 94.228.215.242

This to me is more than "a simple A record", but may not be your problem at all, as it is what I'd expect.  BUT.. if I look up lists.pythonic.nl for it's MX record, I get this:

pythonic.nl

        primary name server = ns1.quickhost.nl

        responsible mail addr = postmaster.pythonic.nl

        serial  = 2010091300

        refresh = 28800 (8 hours)

        retry   = 7200 (2 hours)

        expire  = 604800 (7 days)

        default TTL = 43200 (12 hours)

So it's not looking like it's right to use lists.pythonic.nl for the domain to send to.   Perhaps if you had one of these user's original headers, it would be easier to diagnose.  It's possible they; or Google, are adding characters to the domain part of the name and that's what's causing the odd output.  Also, if you could indicate what a proper address for one of the mailing lists would be (just the part after the @ then I could look at the DNS entries a little better.

--
You received this message because you are subscribed to the Google Groups "Gmail-Users" group.
To post to this group, send email to gmail...@googlegroups.com.
To unsubscribe from this group, send email to gmail-users...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/gmail-users?hl=en.

[Gijs Molenaar]

Hi Zack,

Thanks for the reply!

I'm not sure if I understand your question correctly, but one example
of a mailinglist hosted is mailman at lists dot pythonic dot nl.
Indeed lists.pythonic.nl is a hostname (A record), but as far as I
know, you don't need to add a MX record for a hostname. The weird part
is that it had worked for more than a year now, it is resent that
gmail users started experiencing these problems.

btw, mail.pythonic.nl, bach.pythonic.nl and lists.pythonic.nl are all
the same machine.

Thanks!


- gijs

> > gmail-users...@googlegroups.com<gmail-users%2Bunsu...@googlegroups.com>
> > .

[Zack (Doc)]

Gijs,

You need an MX record for anything that goes after the @ sign in an e-mail address.  So like this list.  The address is gmail...@googlegroups.com.  There is an MX record for googlegroups.com.  It points to a server, which, in turn, has an A record for the actual machine that picks it up.

What is an actual e-mail address that one could use to send a message to the list?  Is there a chance the GMail users who are having this problem are just typing it wrong?

To unsubscribe from this group, send email to gmail-users...@googlegroups.com.

[Gijs Molenaar]

Me again,

What I said wasn't completely true also. I looked it up in the RFC's.A domain, subdomain or hostname doesn't require a MX record, a mailserver wil try to deliver the mail where the domain, subdomain or hostname is pointing to with a A record or CNAME. Only if you want your mail delivered to a diverent machine you need to add a MX record. Still, for a domain it is a good idea to specify a mailserver with a MX record, since then you can also specify a backup server.

To be sure I added a MX record for the hostname, but I don't expect to solve the problem. Also because it was working for such a long time. Let's see and wait what happens. I also tried to increase the TTL, but my DNS provider doesn't support this.

 - gijs

[Gijs Molenaar]

Op 9/15/10 4:38 AM, Zack (Doc) wrote:

Gijs,

Hi Zack,

Thanks for your reply.

You need an MX record for anything that goes after the @ sign in an e-mail address.  So like this list.  The address is gmail...@googlegroups.com.  There is an MX record for googlegroups.com.  It points to a server, which, in turn, has an A record for the actual machine that picks it up.

Yes, googlegroups.com is a domain. lists.pythonic.nl is a hostname, or a A record. A hostname doesn't need a MX. It was working for a long long time like this, and only sometimes it doesn't.

What is an actual e-mail address that one could use to send a message to the list?

I just said that in my previous email adres? It is mailman at lists dot pythonic dot nl.

Is there a chance the GMail users who are having this problem are just typing it wrong?

No, I'm absolutely sure they type it correct.

 - gijs

[Sarah Hill]

Gmail's help for "My domain can't receive mail from Gmail"
http://mail.google.com/support/bin/answer.py?answer=80086#MXToolbox

If you work through the questions,  it says: "visit http://mxtoolbox.com, enter your domain name and click MX Lookup. When the results appear, verify that the MX records are correct, and please run diagnostics on your servers."
It then asks if your servers passed the diagnostics, if your servers did pass the diagnostics, and you answer "yes" to the last question, because you still have problems  - there is a contact link!

[Gijs Molenaar]

On 9/15/10 9:26 PM, Sarah Hill wrote:

Gmail's help for "My domain can't receive mail from Gmail"
http://mail.google.com/support/bin/answer.py?answer=80086#MXToolbox

If you work through the questions,  it says: "visit http://mxtoolbox.com, enter your domain name and click MX Lookup. When the results appear, verify that the MX records are correct, and please run diagnostics on your servers."
It then asks if your servers passed the diagnostics, if your servers did pass the diagnostics, and you answer "yes" to the last question, because you still have problems  - there is a contact link!

This is great, thanks! I feel stupid that I couldn't find this out myself. If I experience the problems again I'll contact google support that way.

Again, thank you very much.

  - gijs