context main-default {
    // outbound dnsbl filtering to catch our own customers that end up on the sbl
    dnsbl   sbl     sbl-xbl.spamhaus.org        "Mail from %s rejected - sbl; see http://www.spamhaus.org/query/bl?ip=%s";
    dnsbl_list  sbl;

    // outbound content filtering to prevent our own customers from sending spam
    content on {
        filter    sbl-xbl.spamhaus.org        "Mail containing %s rejected - sbl; see http://www.spamhaus.org/query/bl?ip=%s";
        uribl     multi.surbl.org             "Mail containing %s rejected - surbl; see http://www.surbl.org/surbl-analysis?d=%s";
        #uribl    multi.uribl.com             "Mail containing %s rejected - uribl; see http://l.uribl.com/?d=%s";
        #uribl    dbl.spamhaus.org            "Mail containing %s rejected - dbl; see http://www.spamhaus.org/query/domain?domain=%s";
        ignore    { include "hosts-ignore.conf"; };
        tld       { include "tld.conf"; };
        html_tags { include "html-tags.conf"; };
        html_limit on 20 "Mail containing excessive bad html tags rejected";
        html_limit off;
        host_limit on 20 "Mail containing excessive host names rejected";
        host_limit soft 20;
        spamassassin        4;
        require_match       yes;
        dcc_greylist        yes;
        dcc_bulk_threshold  50;
    };

    // backscatter prevention - do not send bounces for mail that we accepted but could not forward
    // we only send bounces to our own customers
    env_from unknown {
        "<>"    black;
    };

    // hourly recipient rate limit by smtp auth client id, or unauthenticated mail from address
    // hourly unique ip addresses  by smtp auth client id, or unauthenticated mail from address
    // default hourly rate limit is 30
    // daily rate limits are 4 times the hourly limit
    // default hourly unique ip addresses is 5
    // daily unique ip addresses are 4 times the hourly limit
    rate_limit 30 4 5 4 { // default
        fred 100 10;   // override default limits
        joe  10  2;    // ""
        "sam@somedomain.tld"  500 2;
        "@otherdomain.tld"    100 2;
    };
};

context main {
    dnsbl   localp  partial.blackholes.five-ten-sg.com  "Mail from %s rejected - local; see http://www.five-ten-sg.com/blackhole.php?%s";
    dnsbl   local   blackholes.five-ten-sg.com  "Mail from %s rejected - local; see http://www.five-ten-sg.com/blackhole.php?%s";
    dnsbl   sbl     zen.spamhaus.org            "Mail from %s rejected - sbl; see http://www.spamhaus.org/query/bl?ip=%s";
    dnsbl   xbl     xbl.spamhaus.org            "Mail from %s rejected - xbl; see http://www.spamhaus.org/query/bl?ip=%s";
    dnswl   dnswl.org  list.dnswl.org   2;
    dnsbl_list  local sbl;
    dnswl_list  dnswl.org;
    require_rdns    yes;

    content on {
        filter    sbl-xbl.spamhaus.org        "Mail containing %s rejected - sbl; see http://www.spamhaus.org/query/bl?ip=%s";
        uribl     multi.surbl.org             "Mail containing %s rejected - surbl; see http://www.surbl.org/surbl-analysis?d=%s";
        #uribl    multi.uribl.com             "Mail containing %s rejected - uribl; see http://l.uribl.com/?d=%s";
        #uribl    dbl.spamhaus.org            "Mail containing %s rejected - dbl; see http://www.spamhaus.org/query/domain?domain=%s";
        ignore    { include "hosts-ignore.conf"; };
        tld       { include "tld.conf"; };
        html_tags { include "html-tags.conf"; };
        html_limit off;
        host_limit soft 20;
        spamassassin    5;
        require_match       yes;
        dcc_greylist        yes;
        dcc_bulk_threshold  20;
    };

    generic "^li.*members.linode.com$|^dsl.static.*ttnet.net.tr$|(^|[x.-])(ppp|h|host)?([0-9]{1,3}[x.-](Red-|dynamic[x.-])?){4}"
            "your mail server %s seems to have a generic name";

    white_regex "=example.com=user@yourhostingaccount.com$";

    env_to {
        # !! replace this with your domain names
        # child contexts are not allowed to specify recipient addresses outside these domains
        # if this is a backup-mx, you need to include here domains for which you relay to the primary mx
        include "/etc/mail/local-host-names";
    };

    context whitelist {
        content off {};
        env_to {
            # dcc_to ok { include "/var/dcc/whitecommon"; };
        };
        env_from white {};      # white forces all unmatched from addresses (everyone in this case) to be whitelisted
                                # so all mail TO these env_to addresses is accepted
    };

    context abuse {
        dnsbl_list xbl;
        content off {};
        generic "^$ " " ";      # regex cannot match, to disable generic rdns rejects
        env_to {
            abuse@              # no content filtering on abuse reports
            postmaster@         # ""
        };
        env_from unknown {};    # ignore all parent white/black listing
    };

    context minimal {
        dnsbl_list sbl;
        content on {
            spamassassin        10;
            dcc_bulk_threshold  many;
        };
        generic "^$ " " ";      # regex cannot match, to disable generic rdns rejects
        env_to {
        };
    };

    context blacklist {
        dnsbl_list ;
        dnswl_list ;
        env_to {
            # dcc_to many { include "/var/dcc/whitecommon"; };
        };
        env_from black {};      # black forces all unmatched from addresses (everyone in this case) to be blacklisted
                                # so all mail TO these env_to addresses is rejected
    };

    env_from unknown {
        abuse@  abuse;  # replies to abuse reports use the abuse context
        # dcc_from { include "/var/dcc/whitecommon"; };
    };

    autowhite 90 "autowhite/my-auto-whitelist";
    # install should create /etc/dnsbl/autowhite writable by userid dnsbl
};