Milter-greylist

I just starting using milter-greylist on the email server for my company
and I have to thank the developer and contributors for this software.
It's practically solved our spam problems.  I'm running an FC5 system
and used the rpm from the extra's.  Easy to setup, easy to run, and easy
to customize.

The only problem I seem to have now is dealing with the long delay when
receiving email.  Most of my clients are used to near instant email
delivery.  When I first turned it on, it was greylisting for 30 minutes
and depending on what the sending server retry was, emails were taking
in excess of an hour.

So until I actually run into problems with the program, can I ask for
some opinions on the greylisting time delay and what people have found
to be a good balance of delivery time versus effective spam blocking?  I
just last night reset it to 10m greylisting and that seems to be just as
effective at first glance.  My system services 1 domain with 1 mail
server and roughly 50 clients.

--- In milter-greylist@yahoogroups.com, Timothy Alberts <talberts@...>
wrote:
>
> 
> The only problem I seem to have now is dealing with the long delay when
> receiving email.  Most of my clients are used to near instant email
> delivery.  When I first turned it on, it was greylisting for 30 minutes
> and depending on what the sending server retry was, emails were taking
> in excess of an hour.
> 
> So until I actually run into problems with the program, can I ask for
> some opinions on the greylisting time delay and what people have found
> to be a good balance of delivery time versus effective spam blocking?  I
> just last night reset it to 10m greylisting and that seems to be just as
> effective at first glance.  My system services 1 domain with 1 mail
> server and roughly 50 clients.
>

We use 1 minute and check frequently for long delays and add domains
or IPs to greylist.conf, so that legimitate mail servers that don't
deal well with greylisting don't get greylisted.

At Fri, 13 Oct 2006 16:19:48 -0000,
Ugo Bellavance wrote:
> 
> --- In milter-greylist@yahoogroups.com, Timothy Alberts <talberts@...>
> wrote:
> >
> > 
> > The only problem I seem to have now is dealing with the long delay when
> > receiving email.  Most of my clients are used to near instant email
> > delivery.  When I first turned it on, it was greylisting for 30 minutes
> > and depending on what the sending server retry was, emails were taking
> > in excess of an hour.
> > 
> > So until I actually run into problems with the program, can I ask for
> > some opinions on the greylisting time delay and what people have found
> > to be a good balance of delivery time versus effective spam blocking?  I
> > just last night reset it to 10m greylisting and that seems to be just as
> > effective at first glance.  My system services 1 domain with 1 mail
> > server and roughly 50 clients.
> >
> 
> We use 1 minute and check frequently for long delays and add domains
> or IPs to greylist.conf, so that legimitate mail servers that don't
> deal well with greylisting don't get greylisted.

I apply greylisting only for suspicious hosts which are found in
DNSRBLs or whose IP addresses seem to be dynamic. In this case the
milter-greylist acts as a backdoor to reduce false positives rather
than a filter to catch spammers.

I feel quite many of spammers are listed in either SpamHaus XBL or
SpamCop Blocking List. In contrast most of legitimate mails are not
delayed. If you hate false negatives, consider to apply content
filters.

AIDA Shinra <shinra@...> wrote:

> I feel quite many of spammers are listed in either SpamHaus XBL or
> SpamCop Blocking List. In contrast most of legitimate mails are not
> delayed. If you hate false negatives, consider to apply content
> filters.

How do you cope with the latest nuisance: message with a ham-looking
text, whith a GIF containing the spam message?

-- 
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu@...

--- In milter-greylist@yahoogroups.com, manu@... wrote:
>
> AIDA Shinra <shinra@...> wrote:
> 
> > I feel quite many of spammers are listed in either SpamHaus XBL or
> > SpamCop Blocking List. In contrast most of legitimate mails are not
> > delayed. If you hate false negatives, consider to apply content
> > filters.
> 
> How do you cope with the latest nuisance: message with a ham-looking
> text, whith a GIF containing the spam message?
> 

I'm currently testing this SA plugin: 

http://www.rulesemporium.com/plugins.htm

Ugo

Ugo Bellavance <iolubik@...> wrote:

> I'm currently testing this SA plugin:  
> http://www.rulesemporium.com/plugins.htm

How does it helps? There are legitimate messages with one Small GIF
attached. Moreover, the workaround is easy for spammers: they just have
to add multiple GIF with various sizes...

-- 
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu@...

--- In milter-greylist@yahoogroups.com, manu@... wrote:
>
> Ugo Bellavance <iolubik@...> wrote:
> 
> > I'm currently testing this SA plugin:  
> > http://www.rulesemporium.com/plugins.htm
> 
> How does it helps? There are legitimate messages with one Small GIF
> attached. Moreover, the workaround is easy for spammers: they just have
> to add multiple GIF with various sizes...

I didn't say this kind of spam is easy to catch, I merely said that I
was testing this plugin.