Postfix Address Verification

[Seamus Allan]

Drew Marshall wrote:
>> This looks like a DNS problem. Are you running a cacheing DNS server on
>> this box? Postfix is rejecting with a temporary failure (450) as it is
>> having what it thinks could be a short term problem. I assume you 
>> have set
>> the next hop in the transport map file, have you done this using a name
>> record or IP address? i.e. in the file does it say:
>>
>> validdomain  relay:internal.host
>>
>> or
>>
>> validdomain  relay:[192.168.1.225]
>>
>> Just to make sure this isn't Postfix logging a slight red herring, 
>> can you
>> also let me know what you have under:
>>
>> smtpd_client_restrictions
>> smtpd_sender_restrictions
>>
>> in main.cf
>>
>> The other thing to check is the logs of the internal machine 
>> (Exchange?),
>> just in case there is anything obvious there.
>>
>> Drew
>>
>>
>>   
> Hi,
>
> I am not running a caching DNS server on this box, all DNS queries are 
> passed to our internal DNS server, however this shouldn't be an issue, 
> as you noted because the next hop is dictated by an entry in the 
> transport map, using IP based hosts. This is what I find so confusing, 
> surely Postfix uses this transport map or even the relay_domain map to 
> decide whether a domain is valid or not?
> I did spend the other day looking at the internal mail hub, and there 
> is nothing out of the ordinary in there which would indicate a problem 
> (such as SMTP restrictions because of connection rate or something).
> In my main.cf, I don't have entries for smtpd_client_restrictions or 
> smtpd_sender_restrictions (whether this is bad or not?), and my 
> smtp_receipient_restrictions is as follows:
> smtpd_recipient_restrictions = permit_mynetworks, 
> permit_sasl_authenticated, reject_unauth_destination, 
> reject_non_fqdn_recipient, reject_unknown_recipient_domain, 
> reject_unverified_recipient
>
> It all seems rather tricky, as there is nothing obvious as to why this 
> his happening.
>
> Cheers for the help
>
>
> Seamus
>
> *Seamus Allan*
> Network Engineer
> Rheel Electronics Ltd
>
Anybody got ideas?

Cheers

Seamus
-- 

*Seamus Allan*
Network Engineer
Rheel Electronics Ltd