Re: Moderated posts?
On 10/12/2014 2:11 PM, Brian wrote:
> On Sun 12 Oct 2014 at 18:45:42 +0200, lee wrote:
>
>> Martin Read <zen75502@zen.co.uk> writes:
>>
>>> On 12/10/14 15:53, lee wrote:
>>>> And when they are filtered, does the sender get a message telling him
>>>> that their message hasn't been delivered?
>>>
>>> The requirement in RFC 2821 (the successor to RFC 821 which you've
>>> recently been referring to) section 4.2.5 that a server which issues a
>>> 2yz completion status after final dot must return appropriate
>>> notification to the sender cannot be fulfilled is an unreasonable
>>> demand in the modern era.
>>>
>>> If you wait for all filtering to complete before issuing a response to
>>> final dot, your mail server is vulnerable to denial-of-service attacks
>>> unless you undercook your filtering; if you issue a 2yz status before
>>> filtering is complete, then send the notifications demanded by RFC
>>> 2821 if the deferred filtering results in a rejection, your mail
>>> server is now a public nuisance because of the amount of backscatter
>>> it generates.
>>
>> All this is no reason to violate RFCs.
>
> No RFCs are being violated.
>
> The mail is accepted. What the recipient does with the mail after that
> is outside the scope of an RFC. There is no obligation on the recipient
> to inform the sender that he has ripped up the mail and junked it.
>
> Most mail which comes through my letterbox goes straight into the paper
> recycling box. If I stood outside the front door and told the postperson
> I didn't want it there would be something else involved.
>
>
And, in fact, more and more ISPs are just accepting and discarding
emails to non-existent users because rejecting such email helps spammers
(any non-rejected email must be a valid user).
Jerry
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