relay not working - dns problem ?

[Zalezny Niezalezny]

Dear Colleagues,

for some reason my relay sever is not able to relay messages to the next
hoop. Maybe somebody would be able to support me here.

In the Postfix Log I found this:

Dec  8 13:47:15 ismtp01 mail.info: "postfix-outgoing-25"/smtp[5982]:
51808B1C: to=, relay=none, delay=0.03,
delays=0.01/0.01/0.01/0, dsn=4.4.3, status=deferred (Host or domain name
not found. Name service error for name=domain.fr type=MX: Host not found,
try again)



What I`m planning to do ?

I would like to transfer message from our MS Exchange server to the
external SMTP gateway:
It looks like this:


msexch(LAN) --- > Relay01(LAN) ---> Relay02(LAN) ---> Gateway(DMZ) >
customer(domain.fr)

In this scenario only GatewayDMZ is able to resolve MX records from the
internet.
If only GatewayDMZ is able to resolve MX records why I see that error on
the first relay server - Relay01 ?

On Relay01 I have configured /etc/postfix/transport file like this:

domain.fr relay:Relay02

Why in that case I see that error ?



I will really appreciate for any advice.



Cheeers

Zalezny

Re: relay not working - dns problem ?

[wilfried.es...@essignetz.de]

Am 08.12.2015 um 14:08 schrieb Zalezny Niezalezny:
...

> On Relay01 I have configured /etc/postfix/transport file like this:
> 
> domain.fr relay:Relay02
> 

Hi,

try to use []. They'll stop DNS-Lookups for MX.

domain.fr :[Relay02oritsIP-Adress]


Possibly better solution is using "relayhost"-parameter for getting all
noninternal mail out (http://www.postfix.org/postconf.5.html#relayhost).


Willi