Jerry Geis wrote: > Gents, > > I have added the following to /etc/mail/sendmail.mc and rebuilt it > trying to control spam. I still get about 25 spam messages a day. > Is there something else that can help control spam? > > Thanks > > jerry > --------------------------- > dnl # > dnl # dnsbl - DNS based Blackhole List/Black List/Rejection list > dnl # See http://www.sendmail.org/m4/features.html#dnsbl > dnl # > FEATURE(`dnsbl', `bl.spamcop.net', `"Spam blocked see: > http://spamcop.net/bl.shtml?"$&{client_addr}')dnl > FEATURE(`dnsbl', `relays.ordb.org', `"Spam blocked see: > http://ordb.org/lookup/?host="$&{client_addr}')dnl > FEATURE(`dnsbl', `cbl.abuseat.org', `"Spam blocked see: > http://cbl.abuseat.org/lookup.cgi?ip="$&{client_addr}')dnl > FEATURE(`dnsbl', `sbl.spamhaus.org', `"Spam blocked see: > http://spamhaus.org/query/bl?ip="$&{client_addr}')dnl > FEATURE(`dnsbl', `list.dsbl.org', `"Spam blocked see: > http://dsbl.org/listing?"$&{client_addr}')dnl > dnl # > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos This question is probably inappropriate for this list, but maybe someone can answer it. Let's pretend I have a network behind a firewall. And let's pretend that the users behind that firewall are both beyond my control, and have a non-zero population of idiots. And further, let's pretend that these idiots have done something to land my firewall's internet IP on a blacklist. So now lets pretend I have a different system on the internet, running sendmail, that I would like to use to relay mail out through, for myself and a few carefully selected non-idiot users. And lets further pretend that this server is a secondary MX for a whole bunch of domains and so gets pounded with spam. OK, I set up this server so that it grants RELAY permission in /etc/mail/access to the IP address that is on the blacklist and everything works. Now I see the above post and think that adding dnsbl features to this sendmail might be a good way of reducing inbound spam. So my question is: if my system has granted RELAY permission to a system which is in a dnsbl used by the sendmail configuration, does the sendmail RELAY, or does it deny the connection attempt? Thanks for wading through this completely hypothetical situation. :)