[exim] Re: Can Exim drop TCP connections instead of properly…

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Autor: Paweł Zuzelski
Data:  
Dla: Jeremy Harris via Exim-users
Temat: [exim] Re: Can Exim drop TCP connections instead of properly closing them?
On Sun, Jul 23, 2023 at 06:19:55PM +0100, Jeremy Harris via Exim-users wrote:
> On 23/07/2023 11:04, Paweł Zuzelski via Exim-users wrote:
> > Is it possible for Exim to drop the TCP connection instead of properly
> > rejecting the message? I don't see any option like that in ACLs.
>
> No. Exim really operates at SMTP and TLS levels rather than TCP.
>
> Also: if you did a proper close on the TCP connection (to release
> resources at your end) this will inform the peer, letting them
> release their resource. You are asking, effectively, for a
> firewall-level action.


Got it. Thank you.

> > For some connections (like obvious attempt to send spam or probing for
> > open relays) I would like Exim to just drop the connection without ever
> > properly closing it, so that the client wastes memory waiting for the
> > time out.
>
> Why not just delay, with the SMTP connection held open.
> Spammers do tend to time out their ends pretty quickly;
> unless you are a high-volume site the resource at your end is
> not large.


This makes sense, and seems to be the best option, indeed. Thank you.

(sorry for broken s/mime on the previous message)

--
Paweł

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