Re: postfix uses A record for MX less domains

2017-04-03 Thread Viktor Dukhovni 

> On Apr 3, 2017, at 11:07 AM, Mario Theodoridis  
> wrote:
> 
>> If you own a domain that should not be receiving email, you can prevent
>> MTAs trying to send mail to it by explicitly specifying a null MX in the
>> DNS:
>> 
>>bikinibottom.com. IN MX 0 .
> 
> Good to know, thanks Philip.

Note, this will typically also prevent "the domain" from sending email.
That is, in this example, email from "localp...@bikibottom.com" will be
refused by many if not most receiving domains.

-- 
Viktor.

Re: postfix uses A record for MX less domains

2017-04-03 Thread Mario Theodoridis 

On 03/04/17 16:56, Philip Paeps wrote:

If you own a domain that should not be receiving email, you can prevent
MTAs trying to send mail to it by explicitly specifying a null MX in the
DNS:

bikinibottom.com. IN MX 0 .


Good to know, thanks Philip.

--
Mit Freundlichen Grüßen / Regards

Mario Theodoridis

regify GmbH
Römerstrasse 39 | D-78183 Hüfingen
Amtsgericht Freiburg HRB 709343
Telefon: +49 771 8978 4238

Re: postfix uses A record for MX less domains

2017-04-03 Thread Philip Paeps 
On 2017-03-31 15:01:17 (+0200), Ralf Hildebrandt  wrote:
> * Mario Theodoridis :
> > i'm having a curious issue with our postfix instance.
> > 
> > It seems it is sending emails to a domain's A record when no MX is found.
> > 
> > Is that standard?
> 
> Yes.
> 
> > If so, can i disable this somewhere?
> 
> No.

If you own a domain that should not be receiving email, you can prevent
MTAs trying to send mail to it by explicitly specifying a null MX in the
DNS:

bikinibottom.com. IN MX 0 .

Philip

-- 
Philip Paeps
Senior Reality Engineer
Ministry of Information

Re: postfix uses A record for MX less domains

2017-04-03 Thread Mario Theodoridis 

On 31/03/17 15:01, Ralf Hildebrandt wrote:

* Mario Theodoridis :

Hi everyone,

i'm having a curious issue with our postfix instance.

It seems it is sending emails to a domain's A record when no MX is found.

Is that standard?


Yes.


If so, can i disable this somewhere?


No.


connect to bikinibottom.com[208.73.211.70]:25: Connection refused
to=, relay=none, delay=407,
delays=407/0.01/0.15/0, dsn=4.4.1, status=deferred (connect to
bikinibottom.com[208.73.211.70]:25: Connection refused)


transport_maps:

bikinibottom.com error:This domain does not accept mail



Thank you Ralf

--
Mit Freundlichen Grüßen / Regards

Mario Theodoridis

regify GmbH
Römerstrasse 39 | D-78183 Hüfingen
Amtsgericht Freiburg HRB 709343
Telefon: +49 771 8978 4238

Re: postfix uses A record for MX less domains

2017-03-31 Thread Ralf Hildebrandt 
* Mario Theodoridis :
> Hi everyone,
> 
> i'm having a curious issue with our postfix instance.
> 
> It seems it is sending emails to a domain's A record when no MX is found.
> 
> Is that standard?

Yes.

> If so, can i disable this somewhere?

No.

> connect to bikinibottom.com[208.73.211.70]:25: Connection refused
> to=, relay=none, delay=407, 
> delays=407/0.01/0.15/0, dsn=4.4.1, status=deferred (connect to 
> bikinibottom.com[208.73.211.70]:25: Connection refused)

transport_maps:

bikinibottom.com error:This domain does not accept mail

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