In Exim, is RBL spam rejected prior to being scanned by SpamAssassin?
- by user955664
I've recently been battling spam issues on our mail server. One account in particular was getting hammered with incoming spam. SpamAssassin's memory use is one of our concerns.
What I've done is enable RBLs in Exim. I now see many rejection notices in the Exim log based on the various RBLs, which is good.
However, when I run Eximstats, the numbers seem to be the same as they were prior to the enabling of the RBLs. I am assuming because the email is still logged in some way prior to the rejection. Is that what's happening, or am I missing something else?
Does anyone know if these emails are rejected prior to being processed by SpamAssassin? Or does anyone know how I'd be able to find out? Is there a standard way to generate SpamAssassin stats, similar to Eximstats, so that I could compare the numbers?
Thank you for your time and any advice.
Edit:
Here is the ACL section of my Exim configuration file
######################################################################
# ACLs #
######################################################################
begin acl
# ACL that is used after the RCPT command
check_recipient:
# to block certain wellknown exploits, Deny for local domains if
# local parts begin with a dot or contain @ % ! / |
deny domains = +local_domains
local_parts = ^[.] : ^.*[@%!/|]
# to restrict port 587 to authenticated users only
# see also daemon_smtp_ports above
accept hosts = +auth_relay_hosts
condition = ${if eq {$interface_port}{587} {yes}{no}}
endpass
message = relay not permitted, authentication required
authenticated = *
# allow local users to send outgoing messages using slashes
# and vertical bars in their local parts.
# Block outgoing local parts that begin with a dot, slash, or vertical
# bar but allows them within the local part.
# The sequence \..\ is barred. The usage of @ % and ! is barred as
# before. The motivation is to prevent your users (or their virii)
# from mounting certain kinds of attacks on remote sites.
deny domains = !+local_domains
local_parts = ^[./|] : ^.*[@%!] : ^.*/\\.\\./
# local source whitelist
# accept if the source is local SMTP (i.e. not over TCP/IP).
# Test for this by testing for an empty sending host field.
accept hosts = :
# sender domains whitelist
# accept if sender domain is in whitelist
accept sender_domains = +whitelist_domains
# sender hosts whitelist
# accept if sender host is in whitelist
accept hosts = +whitelist_hosts
accept hosts = +whitelist_hosts_ip
# envelope senders whitelist
# accept if envelope sender is in whitelist
accept senders = +whitelist_senders
# accept mail to postmaster in any local domain, regardless of source
accept local_parts = postmaster
domains = +local_domains
# accept mail to abuse in any local domain, regardless of source
accept local_parts = abuse
domains = +local_domains
# accept mail to hostmaster in any local domain, regardless of source
accept local_parts = hostmaster
domains =+local_domains
# OPTIONAL MODIFICATIONS:
# If the page you're using to notify senders of blocked email of how
# to get their address unblocked will use a web form to send you email so
# you'll know to unblock those senders, then you may leave these lines
# commented out. However, if you'll be telling your senders of blocked
# email to send an email to [email protected], then you should
# replace "errors" with the left side of the email address you'll be
# using, and "example.com" with the right side of the email address and
# then uncomment the second two lines, leaving the first one commented.
# Doing this will mean anyone can send email to this specific address,
# even if they're at a blocked domain, and even if your domain is using
# blocklists.
# accept mail to [email protected], regardless of source
# accept local_parts = errors
# domains = example.com
# deny so-called "legal" spammers"
deny message = Email blocked by LBL - to unblock see http://www.example.com/
# only for domains that do want to be tested against RBLs
domains = +use_rbl_domains
sender_domains = +blacklist_domains
# deny using hostname in bad_sender_hosts blacklist
deny message = Email blocked by BSHL - to unblock see http://www.example.com/
# only for domains that do want to be tested against RBLs
domains = +use_rbl_domains
hosts = +bad_sender_hosts
# deny using IP in bad_sender_hosts blacklist
deny message = Email blocked by BSHL - to unblock see http://www.example.com/
# only for domains that do want to be tested against RBLs
domains = +use_rbl_domains
hosts = +bad_sender_hosts_ip
# deny using email address in blacklist_senders
deny message = Email blocked by BSAL - to unblock see http://www.example.com/
domains = +use_rbl_domains
senders = +blacklist_senders
# By default we do NOT require sender verification.
# Sender verification denies unless sender address can be verified:
# If you want to require sender verification, i.e., that the sending
# address is routable and mail can be delivered to it, then
# uncomment the next line. If you do not want to require sender
# verification, leave the line commented out
#require verify = sender
# deny using .spamhaus
deny message = Email blocked by SPAMHAUS - to unblock see http://www.example.com/
# only for domains that do want to be tested against RBLs
domains = +use_rbl_domains
dnslists = sbl.spamhaus.org
# deny using ordb
# deny message = Email blocked by ORDB - to unblock see http://www.example.com/
# # only for domains that do want to be tested against RBLs
# domains = +use_rbl_domains
# dnslists = relays.ordb.org
# deny using sorbs smtp list
deny message = Email blocked by SORBS - to unblock see http://www.example.com/
# only for domains that do want to be tested against RBLs
domains = +use_rbl_domains
dnslists = dnsbl.sorbs.net=127.0.0.5
# Next deny stuff from more "fuzzy" blacklists
# but do bypass all checking for whitelisted host names
# and for authenticated users
# deny using spamcop
deny message = Email blocked by SPAMCOP - to unblock see http://www.example.com/
hosts = !+relay_hosts
domains = +use_rbl_domains
!authenticated = *
dnslists = bl.spamcop.net
# deny using njabl
deny message = Email blocked by NJABL - to unblock see http://www.example.com/
hosts = !+relay_hosts
domains = +use_rbl_domains
!authenticated = *
dnslists = dnsbl.njabl.org
# deny using cbl
deny message = Email blocked by CBL - to unblock see http://www.example.com/
hosts = !+relay_hosts
domains = +use_rbl_domains
!authenticated = *
dnslists = cbl.abuseat.org
# deny using all other sorbs ip-based blocklist besides smtp list
deny message = Email blocked by SORBS - to unblock see http://www.example.com/
hosts = !+relay_hosts
domains = +use_rbl_domains
!authenticated = *
dnslists = dnsbl.sorbs.net!=127.0.0.6
# deny using sorbs name based list
deny message = Email blocked by SORBS - to unblock see http://www.example.com/
domains =+use_rbl_domains
# rhsbl list is name based
dnslists = rhsbl.sorbs.net/$sender_address_domain
# accept if address is in a local domain as long as recipient can be verified
accept domains = +local_domains
endpass
message = "Unknown User"
verify = recipient
# accept if address is in a domain for which we relay as long as recipient
# can be verified
accept domains = +relay_domains
endpass
verify=recipient
# accept if message comes for a host for which we are an outgoing relay
# recipient verification is omitted because many MUA clients don't cope
# well with SMTP error responses. If you are actually relaying from MTAs
# then you should probably add recipient verify here
accept hosts = +relay_hosts
accept hosts = +auth_relay_hosts
endpass
message = authentication required
authenticated = *
deny message = relay not permitted
# default at end of acl causes a "deny", but line below will give
# an explicit error message:
deny message = relay not permitted
# ACL that is used after the DATA command
check_message:
accept
