[Mimedefang] DNS and MX records

[John Rudd]

On May 15, 2006, at 6:01 AM, Les Mikesell wrote:

> On Mon, 2006-05-15 at 07:43, netguy wrote:
>>>> It was described in a now-expired ietf document
>>>> draft-delany-nullmx-00.txt,
>>>> still available at:
>>>> http://ietfreport.isoc.org/all-ids/draft-delany-nullmx-00.txt
>>
>> This does not answer the question of how to stop spammers from using
>> network resources.  So that is probably very wishfull thinking but if
>> another avenue could be taken away from them...  Spam is sent to
>> domain.tld WITHOUT checking MX records.
>
> If you don't include the domain in local-host-names sendmail
> should reject everything at the RCPT TO step before DATA
> is permitted.  That still consumes some resources but should
> be insignificant compared to the ones you accept and scan.

or, going with the topic of this list, if you wanted to accept mail for 
postmaster and abuse, you could keep the domain in local-host-names, 
but filter out any recipients for that domain (except postmaster and 
abuse) during filter_recipient.