Date: Sun, 13 Feb 2005 20:42:21 -0500 From: Bill Vermillion <bv@wjv.com> To: freebsd-isp@freebsd.org Subject: Re: Sendmail question Message-ID: <20050214014221.GB54164@wjv.com> In-Reply-To: <200502132313.36458.asstec@matik.com.br> References: <1BC9C5447DEF1F4FBE3927A31D6B540404DC08@gehrig.hall.oopz.com> <200502132313.36458.asstec@matik.com.br>
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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@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@a.com curly > > larry@a.com larry > > moe@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@freebsd.org mailing list > > http://lists.freebsd.org/mailman/listinfo/freebsd-isp > > To unsubscribe, send any mail to "freebsd-isp-unsubscribe@freebsd.org" > > -- > > > Infomatik > implementamos asas na sua rede. > (18)3551.3591 (18)8112.7007 > _______________________________________________________ > Participe na lista de seguran?a, > recebendo as mais importantes not?cias na hora > Entre em http://info.matik.com.br e participe. > _______________________________________________________ > Mensagens sem assinatura GPG n?o s?o nossas. > Messages without GPG signature are not from us. > _______________________________________________________ -- Bill Vermillion - bv @ wjv . com
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