On Wed, 16 Feb 2005, Marc Perkel wrote:
> From: Marc Perkel <marc@???>
> To: exim-users@???
> Date: Wed, 16 Feb 2005 08:24:15 -0800
> Subject: [exim] Initial Delay of greeting
>
> What do I do to create an initial delay in the greeting that Exim send out.
> I've been told that some spammers don't wait for the greeting and will create
> an error if I delay for even a few seconds. Thought I'd try it and see how it
> works.
Put an explicit delay in an acl_smtp_connect etc? Not that I've tested
this.
But you can usually get the same effect by doing things like setting:
rfc1413_hosts = *
think about lowering the timeout -- I use 20 seconds -- if you do this.
Also setting:
host_lookup = *
should do it. I use both rfc1413_hosts and host_lookup.
Alternatively using any RBL etc may create enough delay to do the trick.
I use several RBLs.
Seems to work for me. My logs are dotted with lines such as:
2005-02-16 16:33:35 SMTP protocol violation: synchronization error (input
sent without waiting for greeting): rejected connection from
H=82-217-213-36.cable.quicknet.nl [82.217.213.36] I=[138.38.32.23]:25
which looks like yet another trojanned dialup/adsl/broadband host. Not
that I'll be shedding any tears...
--
Dennis Davis, BUCS, University of Bath, Bath, BA2 7AY, UK
D.H.Davis@??? Phone: +44 1225 386101
