| 1 | From: Suresh Ramasubramanian <linux@frodo.hserus.net> |
| 2 | Date: Mon, 11 Aug 2003 11:57:39 +0530 |
| 3 | |
| 4 | I've been seeing a whole bunch of IPs that send me spam / virus mail and |
| 5 | HELOing as one of my own IPs, or as HELO one.of.my.own.domains (or maybe |
| 6 | HELO primary_hostname) |
| 7 | |
| 8 | On the other hand, I have users relaying through my box with AUTH, using |
| 9 | mozilla, which HELO's as "HELO hserus.net" if a hserus.net user relays. |
| 10 | |
| 11 | Here's something to stop this stuff - in acl_check_rcpt: |
| 12 | |
| 13 | [snippet in exim configure file] |
| 14 | |
| 15 | accept hosts = : |
| 16 | |
| 17 | # Accept all authenticated senders |
| 18 | accept authenticated = * |
| 19 | |
| 20 | # Spam control |
| 21 | |
| 22 | # Be polite and say HELO. Reject anything from hosts that havn't given |
| 23 | # a valid HELO/EHLO to us. |
| 24 | deny condition = ${if \ |
| 25 | or{{!def:sender_helo_name}{eq{$sender_helo_name}{}}}{yes}{no}} |
| 26 | message = RFCs mandate HELO/EHLO before mail can be sent |
| 27 | |
| 28 | # Forged hostname - HELOs as my own hostname or domain |
| 29 | deny message = Forged hostname detected in HELO: $sender_helo_name |
| 30 | hosts = !+relay_from_hosts |
| 31 | log_message = Forged hostname detected in HELO: \ |
| 32 | $sender_helo_name |
| 33 | condition = ${lookup {$sender_helo_name} \ |
| 34 | lsearch{/usr/local/etc/exim/local_domains}{yes}{no}} |
| 35 | |
| 36 | # Forged hostname -HELOs as one of my own IPs |
| 37 | deny message = Forged IP detected in HELO: $sender_helo_name |
| 38 | hosts = !+relay_from_hosts |
| 39 | log_message = Forged IP detected in HELO: $sender_helo_name |
| 40 | condition = ${if \ |
| 41 | eq{$sender_helo_name}{$interface_address}{yes}{no}} |
| 42 | |
| 43 | [end snippet] |
| 44 | |