Date: Mon, 16 Oct 2000 21:48:47 -0500 From: Dan Nelson <dnelson@emsphone.com> To: Jan Knepper <jan@smartsoft.cc> Cc: FreeBSD Questions <FreeBSD-Questions@FreeBSD.ORG> Subject: Re: E-Mail collector on the freebsd.org majordomo lists. Message-ID: <20001016214847.A9400@dan.emsphone.com> In-Reply-To: <39EBB823.8B7EE26E@smartsoft.cc>; from "Jan Knepper" on Mon Oct 16 22:23:31 GMT 2000 References: <39EBB823.8B7EE26E@smartsoft.cc>
next in thread | previous in thread | raw e-mail | index | archive | help
In the last episode (Oct 16), Jan Knepper said: > Something just struck me a minute ago as I received spam on an e-mail > address I only used once to post a message on one of the freebsd > majordomo mailing lists. My impression is that some > e-mail-addresses-cd-rom-creating-company is subscribed to one or all > of the list and collects e-mail addresses of people posting to the > lost that way. Is there any easy way to get around this? I think I > noticed that egroups.com strips part of the e-mail address so it > becomes unusable. Only on the webpages. Egroups subscribers always see unmangled emails. > Currently I report any span at http://www.spamcop.net/ but I am > pretty mich getting tired of receiving spam at all. > > Some one have any brilliant idea's???? Create a new userid for each list (a simple user+<random number> would suffice) and block any incoming mail that doesn't CC: the correct list or isn't a reply to a list email? Trying to keep track of recent list traffic could get a bit complicated, but it'd pretty much filter out all spam. At minimum, configure sendmail to use the RBL. RBL, DUL, and RSS are pretty conservative (i.e. if you get mail from a site on one of these lists, it's almost always spam), but I also like orbs. You could also block emails from machines with no reverse DNS or reverse that doesn't match forward DNS: FEATURE(dnsbl)dnl FEATURE(dnsbl,`dialups.mail-abuse.org',`Mail from dial-up $&{client_addr} rejected; see http://mail-abuse.org/dul/enduser.htm')dnl FEATURE(dnsbl,`relays.mail-abuse.org',`Abused email relay $&{client_addr} rejected; see http://mail-abuse.org/rss/')dnl FEATURE(dnsbl,`relays.orbs.org',`Open email relay $&{client_addr} rejected; see http://www.orbs.org/')dnl LOCAL_RULESETS SLocal_check_rcpt # check client name: did it resolve? R$* $: < $&{client_resolve} > R<TEMP> $#error $@ 4.7.1 $: "450 Cannot resolve PTR record for " $&{client_addr} R<FORGED> $#error $@ 5.7.1 $: "550 IP name possibly forged " $&{client_name} R<FAIL> $#error $@ 5.7.1 $: "550 IP name lookup failed " $&{client_name} -- Dan Nelson dnelson@emsphone.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20001016214847.A9400>