Re: How would you provide a 554 rejection notice for spam?

On Tue, 31 Jul 2007 at 18:20 -0400, rickm@ummm-beer.com confabulated:

> John D. Hardin wrote:
>> On Tue, 31 Jul 2007, mouss wrote:
>>
>>> running SA at smtp time requires that the client does not timeout.
>>> so you'd better scan fast! you're also more subject to DOS (your
>>> smtp listeners are busy). compare this to queue and filter...
>>
>> okay, here's a sick idea:
>>
>> (1) MTA completes the SMTP exchange and responds with a 4xx after DATA
>> finishes.
>>
>> (2) MTA passes message off to SA, then stores a hash of message-ID/score.
>> MTA then discards the message.
>>
>> (3) When the remote MTA retries (if it retries) then the MTA looks up the
>> score in the hash and decides whether to 200 or 5xx the message.
>>
>> All of the benefits of both methods! :)
>>
>
> Sort of like grey listing, which I do run on my personal domain, but I
> wouldn't use that method because of the inherent delay caused by the 4xx
> retry.
>
> Neat idea though.

I agree, neat idea. However, all email messages coming into the server would be delayed. Unlike greylisting, where the connection is accepted after the initial 4xx rejection.

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  (_| | Received on Tue Jul 31 19:04:09 2007