[Mailman-Users] Queue problems

[Allan Odgaard]

On 17 Jun 2008, at 18:53, Mark Sapiro wrote:

> Brad Knowles wrote:
>
>> On 6/17/08, Allan Odgaard wrote:
>>
>>> I transferred a lot of list members from a previous list. A dozen  
>>> of these
>>> has left errors like the following in `logs/smtp-failures`:
>>>
>>>    delivery to <<address>> failed with code 450:
>>>    4.1.2 <<address>>: Recipient address rejected:
>>>    Domain not found
>>
>> You're doing DNS validation on your outbound
>> mail.  Don't do that.  Pay attention to the stuff
>> in section 6 of the FAQ, especially including
>> 6.6, 6.8, 6.12, etc....
>
> Also, fix your MTA configuration so it returns a 5xx status, not a 450
> for a non-existant domain.

To the best of my knowledge, this can not be “fixed” (for Postfix). If  
Postfix is unable to obtain DNS settings for a domain, it will treat  
it as a temporary error, and will return 450, regardless of settings  
(and to me this seems correct, as not being able to obtain DNS  
settings is likely because something is down).

If on the other hand it _does_ find a name server for the domain and  
there is no MX record, _then_ can it be treated as a permanent error.

If others should run into this problem  
`reject_unknown_recipient_domain` was the setting I had to disable in  
Postfix’s `smtpd_recipient_restrictions`.