** Andy Smith <andy@???> [2008-01-21 19:25]:
> On Mon, Jan 21, 2008 at 06:56:45PM +0000, Paul Tansom wrote:
> > I'm likely to be using a dedicated server anyway in my DMZ, but
> > I'm not convinced of the value of using two different mail servers
> > over putting together an Exim based solution, and one that does a
> > decent amount of rejecting at the SMTP conversation stage.
>
> One issue with rejecting spam at SMTP time is that if any of your
> users are on mailing lists which get spam, those lists will
> eventually forcibly unsubscribe your users thinking their addresses
> are undeliverable.
>
> I haven't found a good solution to this, so all I do is collect IPs
> of known list servers in a variable. If my Exim is about to issue a
> permanent failure in a connection from one of these, and if the mail
> sent is precedence bulk or list, I just accept it and file it away
> elsewhere instead.
>
> Pretty nasty but as I say I can't think of a better way.
** end quote [Andy Smith]
I hadn't thought of that one to be honest. I guess that's where
whitelisting will help, although it does rely on being told when
somebody subscribes. So long as the spam score isn't too high then
greylisting won't cause any problems to a mailing list since it will
just retry. I've not had any significant spam from any of the lists I'm
on with the exception of the Debian ones. Maybe I've just been lucky :)
I may well greylist everything with a decent spam score to start with,
so perhaps I can move the rejection/ditching off the SMTP connection and
not have too much to deal with.
--
Paul Tansom | Aptanet Ltd. |
http://www.aptanet.com/ | 023 9238 0001
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