On Friday, September 02, 2011 04:49:14 AM Lena@??? wrote:
> Exim already does that by default. Read description of the
> smtp_enforce_sync main configuration option, then telnet to Exim, you'll
> see 3 seconds delay between connection and SMTP banner. If a spambot or an
> abused proxy tries to send HELO before the banner, Exim drops the
> connection.
I just telnetted into one of my servers (they all run the same exim.conf file)
on port 25 and got an immediate reply.
I checked and there's no reference to the option in my exim.conf file.
Yet the rejection is triggered occasionally; my current rejectlog shows it 35
times in approximately 4-1/2 days. So I'm a bit confused.
> SMTP protocol synchronization error (input sent without waiting for
> greeting): rejected connection from
>
> > # Accept hosts who are polite enough to wait rather than just send, as
> > spammers do accept hosts = *
> >
> > delay = 3s
> >
> > # Deny hosts who don't wait
> > deny message = Too quick on the draw - to unblock wait for helo/ehlo
>
> This "deny" is never reached.
I can't test this because I don't use it; I'll check with the gent who
submitted it to me, and ask him. But I believe you're right, as exim is
returning it first.
Can you tell me why my own tests from my desktop on port 25 don't seem to get
delayed?
Thanks.
Jeff
--
Jeff Lasman, Nobaloney Internet Services
Post Office Box 52200, Riverside, CA 92517
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Phone +1 951 643-5345, or see:
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