Milter-greylist

On Sun, Jul 11, 2004 at 07:59:55PM +0200, Emmanuel Dreyfus wrote:
> > I get huge mail bunch to non existing users. They also get
> > autowhite-listed when they are resend earlier than 30 minutes.
> > Is it possible to block this?
> If you have a local alias table for all recipients, you can do that:
> some.user@...   login@...

There is a better way to implement this with sendmail:

1.) Add "FEATURE(blacklist_recipients)" to the ".mc" file used to built
    your sendmail configuration.

2.) Add the domain you are accepting e-mail for to "/etc/mail/relay-domains".

3.) Instead of adding ...

To:domain.com					RELAY

   ... to "/etc/mail/access" add explicit entries like this:

user1@...				RELAY
user2@...				RELAY
user3@...				RELAY
[...]
user99@...				RELAY
To:domain.com					error:5.1.1:550 User unknown

Using a setup like this will make sure that your mail only accepts e-mail
for valid address. The sendmail on my system bounces invalid addresses
without greylisting them:

Jul 11 03:49:03 colwyn sm-mta[25815]: i6B1n0Yf025815: ruleset=check_rcpt, arg1=<fuji@...>, relay=[65.182.128.171], reject=550 5.1.1 <fuji@...>... User unknown
Jul 11 03:49:03 colwyn sm-mta[25815]: i6B1n0Yf025815: from=<Santiago@...>, size=0, class=0, nrcpts=0, proto=SMTP, daemon=MTA, relay=[65.182.128.171]

This is of course only necessary when your system accepts e-mail for
non-local users. Invalid local addresses will always be bounced before
greylisting is applied.

	Kind regards

-- 
Matthias Scheler                                  http://scheler.de/~matthias/