On 01/18/2011 04:20 PM, Martin Gregorie wrote:
> On Tue, 2011-01-18 at 09:00 -0500, Bowie Bailey wrote:
>> On 1/18/2011 4:13 AM, J4 wrote:
>>> I have Dovecot LDA so Sieve might well be a good idea, but I would
>>> like to inform the sender that the Email was dropped as spam, and
>>> avoid backscatter. I don't think I can do this with Sieve/Dovecot LDA.
>> You cannot do this from the delivery agent without creating
>> backscatter. If you want to inform the sender, the only reliable way to
>> do it is to scan the message when it first comes in and simply reject
>> the spam. This way, you never accept the message and the sending system
>> is responsible for notifying the sender that the message did not go through.
>>
> If you're thinking of detecting spam at SMTP time you should consider
> greylisting. When my ISP implemented it the spam I get dropped
> immediately from 80% of my mail to 8%, where its remained ever since.
> After that you can take a view whether you want to:
>
> - scan the remaining mail at SMTP time (and reject spam as you
> originally described)
>
> - use SA as an MTA filter and let the recipient's MUA put it in a spam
> folder or bin depending on what the user decides. Or your MTA filter
> could silently bin spam or feed it to Bayes to be learned as spam.
> Your choice: you just can't reject it at this stage.
>
> - use a procmail recipe to scan mail and either reject spam or pass it
> to the recipient's MUA as above. Use this if you want the recipients
> to have some control over spam recognition, individual Bayes filters,
> etc.
>
> Martin
>
>
Hi Martin,
Thank-you for the advise. I am using postgrey.
S
