Re: [SLUG] inbound email checking

[Phil Scarratt <fil@xxxxxxxxxxx>]

Peter Hardy wrote:
> On Mon, 2008-08-04 at 14:10 +1000, Mary Gardiner wrote:
>> On Tue, Jul 29, 2008, Voytek Eymont wrote:
>>> is there any req on me having an 'apache@' address if I'm sending
>>> emails as such ?
>>>
>>> (i.e., who misconfigured their server ?)
>> Sender address verification is a fairly common anti-spam technique.
>> RFC 2821 allows for mail to be rejected based on local policy, and the
>> remote end has chosen to implement a policy whereby the return address
>> must verifiably exist (in the sense of being able to receive the first
>> part of an SMTP transaction) before accepting mail. So it's not a
>> configuration that violates the protocol, that I can see.
>>
>> Whether it's a totally sensible configuration is another question: it
>> tends to interact badly if the sender address in turn greylists incoming
>> mail, for example. But it's unlikely to be accidental on their part.
> 
> I for one think it's perfectly cromulent. If the sender MX utilises
> greylisting then it'll send back a transient failure message as distinct
> from a permanent 550 failure. At that point, the receiving MX can either
> assume a transient failure means it's normally a valid address and
> accept the mail, or give back its own transient failure - an eye for an
> eye if you like.
> If that's a problem, I'm more inclined to blame it on greylisting.
> Introducing needless artificial delays strikes me as an incredibly ugly
> solution for dealing with spam. 
> 

Can we try changing the subject of this thread? All messages are being
moderated.

Fil