Sendmail question

Sun Feb 13 18:11:33 PST 2005

On Sunday 13 February 2005 23:56, Noah Davidson wrote:
> This is a backup mail server.  The primary mail server is an Exchange 2003
> server.  So when mail is sent to invaliduser at bdomain.com then this server
> sends the mail to the exchange server that is responsible for handling the

you wrote:
> > > I have set up a new FreeBSD box as mainly a backup mail server,
> > > although it is primary for a couple of domains. It is running
> > > sendmail 8.13.3 and it works fine, except for all the spam that

but sorry for not understanding your strange crypt ...

> mail for domain.com.  Since the user does not exist it bounces the mail. 
> Then the root alias gets a copy of the bounced mail.  Is there any way to
> prevent this from happening?  This server should just queue the mail for
> the exchange server until the exchange server is available.
>

but anyway you may use /etc/mailertable and put a line like this for each 
domain you forward and there should no additional mail processing until the 
msg timed out conforming your sendmail.cf settings

.domain.com	smtp:windots.com.br

aditional you need add to your local-host-names the host name as used in the 
domains MX record

> Thanks
> Noah Davidson
>
> ________________________________
>
> From: owner-freebsd-isp at freebsd.org on behalf of Bill Vermillion
> Sent: Sun 2/13/2005 5:42 PM
> To: freebsd-isp at freebsd.org
> Subject: Re: Sendmail question
>
>
>
> I know you'll find this hard to believe, but on Sun, Feb 13, 2005 at 23:13
> ,
>
> Suporte Matik actually admitted to saying:
> > On Sunday 13 February 2005 22:46, Noah Davidson wrote:
> > > The only problem with that approach is that this is a back up
> > > server and the users may not be able to know of all of the
> > > users. Is there any way to not have all of these bounced mail
> > > go to the postmaster / root account.
> >
> > sendmail should reject mail for nonexistent users by default
> > and not forward to root unless you have any strange alias for
> > all but you say bounced mail what confuses me a little bit, but
> > anyway, isn't it that your systema accounts are exploited by
> > the spammers ? so if having 10 domains you may get 10 spams for
> > tty in your root mailbox, to prevent you may try this in your
> > access:
> >
> > tty@    ERROR:"4.2.2:450 No such user here."
> >
> > and so on for each systema account and rebuild the access.db and
> > probably your headache goes away
>
> The problem I have is that when mail is bounced back mail from
> spammers often comes from forged addresses and I get emails
> from the far site indicating there are unknown users.
>
> So I find routing noexistant users to /dev/null is more productive.
> While it's not exactly the best way to do it, there are so many
> bogus addresses sending mail I haven't found a good alternative.
>
> One site we handle has one of those strong standalone names that
> don't require any advertising to come up #1 on google or msn and
> when it finally hit 300,000 spams/day for that one domain I took
> out the MX records.
>
> I use the access.db for blocking known places and I won't send
> anything back at all - I used the DISCARD verb as sending messages
> back does nothing but generate more traffic.
>
> > > ________________________________
> > >
> > > From: Bill Vermillion [mailto:bv at wjv.com]
> > > Sent: Sun 2/13/2005 2:30 PM
> > > To: Noah Davidson
> > > Cc: FreeBSD-ISP List
> > > Subject: Re: Sendmail question
> > >
> > >
> > >
> > > Ashes to ashes, and DOS to DOS Noah Davidson was heard to say
> > >
> > > on or about Sun, Feb 13, 2005 at 14:10 :
> > > > I have set up a new FreeBSD box as mainly a backup mail server,
> > > > although it is primary for a couple of domains. It is running
> > > > sendmail 8.13.3 and it works fine, except for all the spam that
> > > > is being sent to it to bad email addresses. I have aliased
> > > > the root account to an email group on another server so that
> > > > someone reads the root mail. The problem is that all the mail
> > > > that spammers are sending to address that do not exist get
> > > > bounced and the root account a notification (I believe it
> > > > is the postmaster alias which is aliased to root). Is there
> > > > any way to not have these notifications sent out. They are
> > > > filling up the mail boxes. I just want the return to sender, but
> > > > not to the root / postmaster as well. I have tried using the
> > > > confCOPY_ERRORS_TO in my .mc file, but that just sends it to an
> > > > additional account as well.
> > >
> > > Making assumptions that your sendmail is receiving bogus mail
> > > for accounts that you have sendmail receive here is approach you
> > > can take.
> > >
> > > Assume you have domains  a.com b.com and c.com and your
> > > local-host-names has those.
> > >
> > > Then you need to find out what users you have for each domain
> > >
> > > If you have curly larry and moe on a.com and no one else, then you
> > > can build a virtualusrtable that looks like this.
> > >
> > > curly at a.com     curly
> > > larry at a.com     larry
> > > moe at a.com       moe
> > > @a.com          nouser
> > >
> > > And the accnount 'nouser' will be in your /etc/mail/aliases
> > > file and will look like this:
> > >
> > > nouser:  /dev/null
> > >
> > > Run make in /etc/mail to create virtusertable.db and aliases.db
> > > and that should get rid of the bogus names going to root.
> > >
> > > I find the virtualusertable to be quite handy for elminating a lot
> > > of junk.   It will only be a problem if you have a large user
> > > base or lots of domains.
> > >
> > > Bill
> > > --
> > > Bill Vermillion - bv @ wjv . com
> > >
> > >
> > > _______________________________________________
> > > freebsd-isp at freebsd.org mailing list
> > > http://lists.freebsd.org/mailman/listinfo/freebsd-isp
> > > To unsubscribe, send any mail to "freebsd-isp-unsubscribe at freebsd.org"
> >
> > --
> >
> >
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> --
> Bill Vermillion - bv @ wjv . com
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-- 

Infomatik
 implementamos asas na sua rede.
  (18)3551.3591 (18)8112.7007
_______________________________________________________
Participe na lista de segurança, 
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