Re: Moderated posts?

[lee <lee@yagibdah.de>]

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.

Besides, the idea is to avoid content filtering and to reject a message
instead of accepting it.


-- 
Again we must be afraid of speaking of daemons for fear that daemons
might swallow us.  Finally, this fear has become reasonable.