[plug] cannot send mail to certain domains

Wed Feb 3 17:11:34 WST 2010

Jon, In relation to what we talked about, My Hostname & DNS Client 
settings* have the following options:

(*The config file (debian) is : /etc/nsswitch.conf)

files mdns4_minimal [NOTFOUND=return] dns mdns4

where 'files' refers to local config files... ie 'hosts'

Hope that helps.

P.

Jon L Miller wrote:
> When I ping mmtlnx.mmtnetworks.com.au I do get the internal IP address.
>
> Jon
>
> -----Original Message-----
> From: plug-bounces at plug.org.au [mailto:plug-bounces at plug.org.au] On Behalf
> Of Peter
> Sent: Wednesday, 3 February 2010 2:14 PM
> To: plug at plug.org.au
> Subject: Re: [plug] cannot send mail to certain domains
>
> Jon L Miller wrote:
>   
>> Hi Peter,
>> Yes, I have an in-house mail server with a private IP. 
>> Yes I also had 2 NS servers that had public IP and they are now turned
>>     
> off.
>   
>> So I moved my clients and my DNS information off-site to MelbourneIT
>>     
> (MIT).
>   
>> The mail server was configured to use the local DNS servers, once they
>>     
> (NS)
>   
>> were turned off; the mail server was configured to use the off-site NS
>> (MIT).
>> >From the server I can ping both the local IP and the external IP (Cisco
>> router external interface). The Cisco is set to NAT inside traffic to the
>> external IP and all traffic that is bound for the external IP is NAT back
>>     
> to
>   
>> the inside server(s) soon to be 1.
>>
>> All the DNS information A and MX pointer are handled by MIT; Amnet handles
>> the rDNS information.  
>> The internal servers are configured (resolv.conf) to look to Telstra and
>> Amnet.  Reason, when a friend of mine and myself did a comparison we found
>> that the MIT servers resolves hotmail.com as something completely
>>     
> different
>   
>> than what Telstra and Amnet did.  Therefore I decided to use Telstra as
>>     
> the
>   
>> primary and Amnet as a secondary NS.
>>
>> Currently the only incoming mail is from plug... gotta like it.
>>
>> Jon
>>
>>
>>
>>   
>>     
> OK, so I have the correct 'picture' in my head.
>
> If you do a ping from the mail server:   'ping mmtnetworks.com.au', what 
> IP address do you get in reply?
>
> A ping from the local server should return it's internal 192.....  
> address and NOT the external 203.... address
>
> Is this the case?
>
> .... just read your last e-mail...
>
> Your hosts file should also contain  'mmtnetworks.com.au' and/or 
> 'mail.mmtnetworks.com.au'  (not just mntlnx.....)
>
> Your MX record: 
>
> ;; QUESTION SECTION:
> ;mmtnetworks.com.au.        IN    MX
>
> ;; ANSWER SECTION:
> mmtnetworks.com.au.    86400    IN    MX    10 mail.mmtnetworks.com.au.
>
> ....
>
> So mail (from the Internet) is being sent to mail.mmtnetworks.com.au and 
> not mntlnx.mmtnetworks.com.au  (the name you have in your hosts file)......
>
> If you ping 'mail.mmtnetworks.com.au from the server, what do you get?
>
>
>
> P.
>
>
>   
>> -----Original Message-----
>> From: plug-bounces at plug.org.au [mailto:plug-bounces at plug.org.au] On Behalf
>> Of Peter
>> Sent: Wednesday, 3 February 2010 1:25 PM
>> To: plug at plug.org.au
>> Subject: Re: [plug] cannot send mail to certain domains
>>
>> Jon Miller wrote:
>>   
>>     
>>> Hi Matt,
>>> Yes I understand they are two separate issue, unfortunately this 
>>> server has several issues, so I'm asking questions not in any 
>>> particular order.  I'll change that so that we can be on the same page 
>>> at the same time.
>>>
>>> ok first thing first
>>> There is mention of the internal ip address in the
>>>       
> /etc/postfix/transport.
>   
>>> Is there supposed to be anything in there?
>>>
>>> Jon
>>>
>>>
>>>
>>>     
>>>       
>>>> Date: Wed, 3 Feb 2010 12:34:15 +0800
>>>> From: zombie at penguincare.com.au
>>>> To: plug at plug.org.au
>>>> Subject: RE: [plug] cannot send mail to certain domains
>>>>
>>>> Hi Jon
>>>>
>>>> You seem to be confusing the two seperate issues here.
>>>>
>>>> The "cannot send mail to certain domains" is a DNS issue. The "I can 
>>>>       
>>>>         
>>> not
>>>     
>>>       
>>>> receive email" is a local postfix configuration issue.
>>>>
>>>> On Wed, 3 Feb 2010, quoth Jon Miller:
>>>>
>>>>       
>>>>         
>>>>> Feb 3 12:22:07 mmtlnx postfix/smtp[25064]: 4B24D365E2:
>>>>> to=<jlmiller at mmtnetworks.com.au>, relay=none, delay=2, status=bounced
>>>>> (mail for 192.168.2.247 loops back to myself)
>>>>>         
>>>>>           
>>>> Where did the 192.168.2.247 come from?
>>>>
>>>> Is that anywhere in your postfix/main.cf or /etc/aliases or 
>>>>       
>>>>         
>>> /etc/postfix/virtual?
>>>     
>>>       
>>>>> What I do not understand is why it's still looping back to the server.
>>>>>         
>>>>>           
>>>> Because the server doesn't realise the message is for itself, so it 
>>>>       
>>>>         
>>> tries
>>>     
>>>       
>>>> to pass it on, only to discover it is talking to itself.
>>>>
>>>> - Matt
>>>> _______________________________________________
>>>> PLUG discussion list: plug at plug.org.au
>>>> http://www.plug.org.au/mailman/listinfo/plug
>>>> Committee e-mail: committee at plug.linux.org.au
>>>>       
>>>>         
>>> ------------------------------------------------------------------------
>>>
>>> _______________________________________________
>>> PLUG discussion list: plug at plug.org.au
>>> http://www.plug.org.au/mailman/listinfo/plug
>>> Committee e-mail: committee at plug.linux.org.au
>>>   
>>>     
>>>       
>> Hi Jon,
>>
>> Can I ask for a bit of general clarification (I've only been skimming 
>> you e-mails)? 
>>
>> If I understand you correctly, you have an in-house mail server (private 
>> IP) and you had a DNS (in house?) but moved this off site to MelbourneIT 
>> hosted DNS servers.....    Is that right?
>>
>> If your mail server was configured to use a local DNS but is now looking 
>> to the web (external DNS) it will get confused. 
>>
>> Eg.  If you ping mmtnetworks.com.au from the server, does it reply 
>> 192.168.2.247 or 203.153.225.77 ?    If the server itself thinks that 
>> mmtnetworks.com.au is out on the the internet (203.153.225.77), local 
>> delivery won't work:  You cannot send and receive mail through the same 
>> physical connection.
>>
>> If you do not have an in-house DNS, you need to make sure any local 
>> domains are (at the very least) in the 'hosts' file on the local server 
>> and /or in your DHCP config for other machines on your network.
>>
>> Or did I completely misunderstand what you are trying to do?
>>
>> Cheers,
>> Peter
>> _______________________________________________
>> PLUG discussion list: plug at plug.org.au
>> http://www.plug.org.au/mailman/listinfo/plug
>> Committee e-mail: committee at plug.linux.org.au
>>
>> _______________________________________________
>> PLUG discussion list: plug at plug.org.au
>> http://www.plug.org.au/mailman/listinfo/plug
>> Committee e-mail: committee at plug.linux.org.au
>>
>>
>>   
>>     
>
> _______________________________________________
> PLUG discussion list: plug at plug.org.au
> http://www.plug.org.au/mailman/listinfo/plug
> Committee e-mail: committee at plug.linux.org.au
>
> _______________________________________________
> PLUG discussion list: plug at plug.org.au
> http://www.plug.org.au/mailman/listinfo/plug
> Committee e-mail: committee at plug.linux.org.au
>
>
>   