Re: [exim] acl_smtp_header. How to save, at least, traffic?

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Συντάκτης: Heiko Schlittermann
Ημερομηνία:  
Προς: exim-users
Αντικείμενο: Re: [exim] acl_smtp_header. How to save, at least, traffic?
meerkat@??? <meerkat@???> (Sa 02 Dez 2006 22:38:41 CET):
> Hello!
>
> I am a novice Exim user, here it is my stupid question:
> Is there a way do not receive a message entirely while blocking unwanted attachments?
> Receipts like that, I found in STFW:
>
>    acl_check_data: \ deny message = "no pasaran" \ demime = bat:exe ...

>
> works fine, but "bad" file is transfered completely.
> Decision to decline it, I guess, might be done after headers read.
>
>
> The same is for filtering based on headers content. Examples, I found, all place rules like that:
>
>    deny condition = ${if !def:h_Message-ID:{1}} \ message = Message SHOULD have Message-ID

>
> in the acl_smtp_data section. How can that useless transfer of a message body be stoped?
>
> In other words: is there something like acl_smtp_headers or how this could be "emulated"?


SMTP has no idea of the message headers. The message headers are part
of the message. The client sends "DATA", expects some acknoledge and
than it feeds the complete message to the server, without expecting some
server response before sending the final ".". Thus there's no way to
tell the client that you're not interested in the rest of the data.

Even dropping the connection wouldn't help, since a client will start
sending the message again.


    Best regards from Dresden
    Viele Grüße aus Dresden
    Heiko Schlittermann
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