Milter-greylist

Examining my greylist.db I find a large number of whitelisted addresses
don't have 
sender e-mail addresses, and by in large (I'd say close to 99% of the 
emails are being sent to non-existent users - in other words they are all
spam).

How do I configure Milter-Greylist to blacklist these e-mails or blacklist
people sending to non-existent email addresses (which can be problematic if
someone misspells a username?

Thx

Wayne

Hi,

> check milter-ahead to reject invalid users.

Or scam-back which does the same thing but is GPL'ed.

Regards,

Michael.

> On Wed, 2008-03-19 at 16:52 -0400, Wayne Spivak wrote:
> > Examining my greylist.db I find a large number of whitelisted
> > addresses
> > don't have 
> > sender e-mail addresses, and by in large (I'd say close to 99% of the 
> > emails are being sent to non-existent users - in other words they are
> > all
> > spam).
> > 
> > How do I configure Milter-Greylist to blacklist these e-mails or
> > blacklist
> > people sending to non-existent email addresses (which can be
> > problematic if
> > someone misspells a username?
> > 
> > Thx
> > 
> > Wayne
> > 
> > 
> > 
> > 
> > 
> >
> 
> ----
> Eduardo Casarero
> Informatica Avanzada SRL
> Email: eduardo.casarero@...
> Tel: (054) 011-52353995 int. 207
------- End of Original Message -------

Wayne Spivak <WSpivak@...> wrote:

> How do I configure Milter-Greylist to blacklist these e-mails or blacklist
> people sending to non-existent email addresses (which can be problematic if
> someone misspells a username?

I have ACL that pull per-user filtering settings from a LDAP directory.
If nothing is found, the recipient address does not exists in the
directory, and the final ACL rejects the transaction.

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

Thank you all for your suggestions - I'll investigate.

Wayne 




Wayne Spivak <WSpivak@... <mailto:WSpivak%40sbanetweb.com> >
wrote:

> How do I configure Milter-Greylist to blacklist these e-mails or blacklist
> people sending to non-existent email addresses (which can be problematic
if
> someone misspells a username?

I think that milter-ahead is not a good solution - you put all the
burden of dictionary attacks / other malicious activities to your
internal mail server.
A perfect solution is a commercial sendmail which has support for LDAP
lookup.
For those (like me) who use the opensource alternative I would suggest
creating a cron-job that would feed the 'access' sendmail database with
a list of valid recipients. In my case the cron script gathers the
recipients from AD.

This way can achieve the following advantages:
- no sendmail or milter software is necessary to be allowed to connect
to your internal LDAP server.
- in case of milter crash, you still continue filtering invalid recipients
- you remove quite some load from milter-greylist
- you can introduce the sendmail's bad RCPT throttling to avoid
dictionary attacks (BAD_RCPT_THROTTLE)
- much better solution than milter-ahead or similar

Ondrej

Wayne Spivak wrote:

>
> Examining my greylist.db I find a large number of whitelisted addresses
> don't have
> sender e-mail addresses, and by in large (I'd say close to 99% of the
> emails are being sent to non-existent users - in other words they are all
> spam).
>
> How do I configure Milter-Greylist to blacklist these e-mails or blacklist
> people sending to non-existent email addresses (which can be
> problematic if
> someone misspells a username?
>
> Thx
>
> Wayne
>
>