--- /dev/null
+
+### acl/30_exim4-config_check_rcpt
+#################################
+
+# This access control list is used for every RCPT command in an incoming
+# SMTP message. The tests are run in order until the address is either
+# accepted or denied.
+#
+acl_check_rcpt:
+
+ # Accept if the source is local SMTP (i.e. not over TCP/IP). We do this by
+ # testing for an empty sending host field.
+ accept
+ hosts = :
+
+
+ # The following section of the ACL is concerned with local parts that contain
+ # certain non-alphanumeric characters. Dots in unusual places are
+ # handled by this ACL as well.
+ #
+ # Non-alphanumeric characters other than dots are rarely found in genuine
+ # local parts, but are often tried by people looking to circumvent
+ # relaying restrictions. Therefore, although they are valid in local
+ # parts, these rules disallow certain non-alphanumeric characters, as
+ # a precaution.
+ #
+ # Empty components (two dots in a row) are not valid in RFC 2822, but Exim
+ # allows them because they have been encountered. (Consider local parts
+ # constructed as "firstinitial.secondinitial.familyname" when applied to
+ # a name without a second initial.) However, a local part starting
+ # with a dot or containing /../ can cause trouble if it is used as part of a
+ # file name (e.g. for a mailing list). This is also true for local parts that
+ # contain slashes. A pipe symbol can also be troublesome if the local part is
+ # incorporated unthinkingly into a shell command line.
+ #
+ # These ACL components will block recipient addresses that are valid
+ # from an RFC2822 point of view. We chose to have them blocked by
+ # default for security reasons.
+ #
+ # If you feel that your site should have less strict recipient
+ # checking, please feel free to change the default values of the macros
+ # defined in main/01_exim4-config_listmacrosdefs or override them from a
+ # local configuration file.
+ #
+ # Two different rules are used. The first one has a quite strict
+ # default, and is applied to messages that are addressed to one of the
+ # local domains handled by this host.
+
+ # The default value of CHECK_RCPT_LOCAL_LOCALPARTS is defined in
+ # main/01_exim4-config_listmacrosdefs:
+ # CHECK_RCPT_LOCAL_LOCALPARTS = ^[.] : ^.*[@%!/|`#&?]
+ # This blocks local parts that begin with a dot or contain a quite
+ # broad range of non-alphanumeric characters.
+ .ifdef CHECK_RCPT_LOCAL_LOCALPARTS
+ deny
+ domains = +local_domains
+ local_parts = CHECK_RCPT_LOCAL_LOCALPARTS
+ message = restricted characters in address
+ .endif
+
+
+ # The second rule applies to all other domains, and its default is
+ # considerably less strict.
+
+ # The default value of CHECK_RCPT_REMOTE_LOCALPARTS is defined in
+ # main/01_exim4-config_listmacrosdefs:
+ # CHECK_RCPT_REMOTE_LOCALPARTS = ^[./|] : ^.*[@%!`#&?] : ^.*/\\.\\./
+
+ # It allows local users to send outgoing messages to sites
+ # that use slashes and vertical bars in their local parts. It blocks
+ # local parts that begin with a dot, slash, or vertical bar, but allows
+ # these characters within the local part. However, the sequence /../ is
+ # barred. The use of some other non-alphanumeric characters is blocked.
+ # Single quotes might probably be dangerous as well, but they're
+ # allowed by the default regexps to avoid rejecting mails to Ireland.
+ # The motivation here is to prevent local users (or local users' malware)
+ # from mounting certain kinds of attack on remote sites.
+ .ifdef CHECK_RCPT_REMOTE_LOCALPARTS
+ deny
+ domains = !+local_domains
+ local_parts = CHECK_RCPT_REMOTE_LOCALPARTS
+ message = restricted characters in address
+ .endif
+
+
+ # Accept mail to postmaster in any local domain, regardless of the source,
+ # and without verifying the sender.
+ #
+ accept
+ .ifndef CHECK_RCPT_POSTMASTER
+ local_parts = postmaster
+ .else
+ local_parts = CHECK_RCPT_POSTMASTER
+ .endif
+ domains = +local_domains : +relay_to_domains
+
+
+ # Deny unless the sender address can be verified.
+ #
+ # This is disabled by default so that DNSless systems don't break. If
+ # your system can do DNS lookups without delay or cost, you might want
+ # to enable this feature.
+ #
+ # This feature does not work in smarthost and satellite setups as
+ # with these setups all domains pass verification. See spec.txt chapter
+ # 39.31 with the added information that a smarthost/satellite setup
+ # routes all non-local e-mail to the smarthost.
+ .ifdef CHECK_RCPT_VERIFY_SENDER
+ deny
+ message = Sender verification failed
+ !acl = acl_local_deny_exceptions
+ !verify = sender
+ .endif
+
+ # Verify senders listed in local_sender_callout with a callout.
+ #
+ # In smarthost and satellite setups, this causes the callout to be
+ # done to the smarthost. Verification will thus only be reliable if the
+ # smarthost does reject illegal addresses in the SMTP dialog.
+ deny
+ !acl = acl_local_deny_exceptions
+ senders = ${if exists{CONFDIR/local_sender_callout}\
+ {CONFDIR/local_sender_callout}\
+ {}}
+ !verify = sender/callout
+
+
+ # Accept if the message comes from one of the hosts for which we are an
+ # outgoing relay. It is assumed that such hosts are most likely to be MUAs,
+ # so we set control=submission to make Exim treat the message as a
+ # submission. It will fix up various errors in the message, for example, the
+ # lack of a Date: header line. If you are actually relaying out out from
+ # MTAs, you may want to disable this. If you are handling both relaying from
+ # MTAs and submissions from MUAs you should probably split them into two
+ # lists, and handle them differently.
+
+ # Recipient verification is omitted here, because in many cases the clients
+ # are dumb MUAs that don't cope well with SMTP error responses. If you are
+ # actually relaying out from MTAs, you should probably add recipient
+ # verification here.
+
+ # Note that, by putting this test before any DNS black list checks, you will
+ # always accept from these hosts, even if they end up on a black list. The
+ # assumption is that they are your friends, and if they get onto black
+ # list, it is a mistake.
+ accept
+ hosts = +relay_from_hosts
+ control = submission/sender_retain
+
+
+ # Accept if the message arrived over an authenticated connection, from
+ # any host. Again, these messages are usually from MUAs, so recipient
+ # verification is omitted, and submission mode is set. And again, we do this
+ # check before any black list tests.
+ accept
+ authenticated = *
+ control = submission/sender_retain
+
+
+ # Insist that any other recipient address that we accept is either in one of
+ # our local domains, or is in a domain for which we explicitly allow
+ # relaying. Any other domain is rejected as being unacceptable for relaying.
+ require
+ message = relay not permitted
+ domains = +local_domains : +relay_to_domains
+
+
+ # We also require all accepted addresses to be verifiable. This check will
+ # do local part verification for local domains, but only check the domain
+ # for remote domains.
+ require
+ verify = recipient
+
+
+ # Verify recipients listed in local_rcpt_callout with a callout.
+ # This is especially handy for forwarding MX hosts (secondary MX or
+ # mail hubs) of domains that receive a lot of spam to non-existent
+ # addresses. The only way to check local parts for remote relay
+ # domains is to use a callout (add /callout), but please read the
+ # documentation about callouts before doing this.
+ deny
+ !acl = acl_local_deny_exceptions
+ recipients = ${if exists{CONFDIR/local_rcpt_callout}\
+ {CONFDIR/local_rcpt_callout}\
+ {}}
+ !verify = recipient/callout
+
+
+ # CONFDIR/local_sender_blacklist holds a list of envelope senders that
+ # should have their access denied to the local host. Incoming messages
+ # with one of these senders are rejected at RCPT time.
+ #
+ # The explicit white lists are honored as well as negative items in
+ # the black list. See exim4-config_files(5) for details.
+ deny
+ message = sender envelope address $sender_address is locally blacklisted here. If you think this is wrong, get in touch with postmaster
+ !acl = acl_local_deny_exceptions
+ senders = ${if exists{CONFDIR/local_sender_blacklist}\
+ {CONFDIR/local_sender_blacklist}\
+ {}}
+
+
+ # deny bad sites (IP address)
+ # CONFDIR/local_host_blacklist holds a list of host names, IP addresses
+ # and networks (CIDR notation) that should have their access denied to
+ # The local host. Messages coming in from a listed host will have all
+ # RCPT statements rejected.
+ #
+ # The explicit white lists are honored as well as negative items in
+ # the black list. See exim4-config_files(5) for details.
+ deny
+ message = sender IP address $sender_host_address is locally blacklisted here. If you think this is wrong, get in touch with postmaster
+ !acl = acl_local_deny_exceptions
+ hosts = ${if exists{CONFDIR/local_host_blacklist}\
+ {CONFDIR/local_host_blacklist}\
+ {}}
+
+
+ # Warn if the sender host does not have valid reverse DNS.
+ #
+ # If your system can do DNS lookups without delay or cost, you might want
+ # to enable this.
+ # If sender_host_address is defined, it's a remote call. If
+ # sender_host_name is not defined, then reverse lookup failed. Use
+ # this instead of !verify = reverse_host_lookup to catch deferrals
+ # as well as outright failures.
+ .ifdef CHECK_RCPT_REVERSE_DNS
+ warn
+ message = X-Host-Lookup-Failed: Reverse DNS lookup failed for $sender_host_address (${if eq{$host_lookup_failed}{1}{failed}{deferred}})
+ condition = ${if and{{def:sender_host_address}{!def:sender_host_name}}\
+ {yes}{no}}
+ .endif
+
+
+ # Use spfquery to perform a pair of SPF checks (for details, see
+ # http://www.openspf.org/)
+ #
+ # This is quite costly in terms of DNS lookups (~6 lookups per mail). Do not
+ # enable if that's an issue. Also note that if you enable this, you must
+ # install "libmail-spf-query-perl" which provides the spfquery command.
+ # Missing libmail-spf-query-perl will trigger the "Unexpected error in
+ # SPF check" warning.
+ .ifdef CHECK_RCPT_SPF
+ deny
+ message = [SPF] $sender_host_address is not allowed to send mail from ${if def:sender_address_domain {$sender_address_domain}{$sender_helo_name}}. \
+ Please see http://www.openspf.org/Why?scope=${if def:sender_address_domain {mfrom}{helo}};identity=${if def:sender_address_domain {$sender_address}{$sender_helo_name}};ip=$sender_host_address
+ log_message = SPF check failed.
+ !acl = acl_local_deny_exceptions
+ condition = ${run{/usr/bin/spfquery --ip \"$sender_host_address\" --mail-from \"$sender_address\" --helo \"$sender_helo_name\"}\
+ {no}{${if eq {$runrc}{1}{yes}{no}}}}
+
+ defer
+ message = Temporary DNS error while checking SPF record. Try again later.
+ condition = ${if eq {$runrc}{5}{yes}{no}}
+
+ warn
+ message = Received-SPF: ${if eq {$runrc}{0}{pass}{${if eq {$runrc}{2}{softfail}\
+ {${if eq {$runrc}{3}{neutral}{${if eq {$runrc}{4}{unknown}{${if eq {$runrc}{6}{none}{error}}}}}}}}}}
+ condition = ${if <={$runrc}{6}{yes}{no}}
+
+ warn
+ log_message = Unexpected error in SPF check.
+ condition = ${if >{$runrc}{6}{yes}{no}}
+
+ # Support for best-guess (see http://www.openspf.org/developers-guide.html)
+ warn
+ message = X-SPF-Guess: ${run{/usr/bin/spfquery --ip \"$sender_host_address\" --mail-from \"$sender_address\" \ --helo \"$sender_helo_name\" --guess true}\
+ {pass}{${if eq {$runrc}{2}{softfail}{${if eq {$runrc}{3}{neutral}{${if eq {$runrc}{4}{unknown}\
+ {${if eq {$runrc}{6}{none}{error}}}}}}}}}}
+ condition = ${if <={$runrc}{6}{yes}{no}}
+
+ defer
+ message = Temporary DNS error while checking SPF record. Try again later.
+ condition = ${if eq {$runrc}{5}{yes}{no}}
+ .endif
+
+
+ # Check against classic DNS "black" lists (DNSBLs) which list
+ # sender IP addresses
+ .ifdef CHECK_RCPT_IP_DNSBLS
+ warn
+ message = X-Warning: $sender_host_address is listed at $dnslist_domain ($dnslist_value: $dnslist_text)
+ log_message = $sender_host_address is listed at $dnslist_domain ($dnslist_value: $dnslist_text)
+ dnslists = CHECK_RCPT_IP_DNSBLS
+ .endif
+
+
+ # Check against DNSBLs which list sender domains, with an option to locally
+ # whitelist certain domains that might be blacklisted.
+ #
+ # Note: If you define CHECK_RCPT_DOMAIN_DNSBLS, you must append
+ # "/$sender_address_domain" after each domain. For example:
+ # CHECK_RCPT_DOMAIN_DNSBLS = rhsbl.foo.org/$sender_address_domain \
+ # : rhsbl.bar.org/$sender_address_domain
+ .ifdef CHECK_RCPT_DOMAIN_DNSBLS
+ warn
+ message = X-Warning: $sender_address_domain is listed at $dnslist_domain ($dnslist_value: $dnslist_text)
+ log_message = $sender_address_domain is listed at $dnslist_domain ($dnslist_value: $dnslist_text)
+ !senders = ${if exists{CONFDIR/local_domain_dnsbl_whitelist}\
+ {CONFDIR/local_domain_dnsbl_whitelist}\
+ {}}
+ dnslists = CHECK_RCPT_DOMAIN_DNSBLS
+ .endif
+
+
+ # This hook allows you to hook in your own ACLs without having to
+ # modify this file. If you do it like we suggest, you'll end up with
+ # a small performance penalty since there is an additional file being
+ # accessed. This doesn't happen if you leave the macro unset.
+ .ifdef CHECK_RCPT_LOCAL_ACL_FILE
+ .include CHECK_RCPT_LOCAL_ACL_FILE
+ .endif
+
+
+ #############################################################################
+ # This check is commented out because it is recognized that not every
+ # sysadmin will want to do it. If you enable it, the check performs
+ # Client SMTP Authorization (csa) checks on the sending host. These checks
+ # do DNS lookups for SRV records. The CSA proposal is currently (May 2005)
+ # an Internet draft. You can, of course, add additional conditions to this
+ # ACL statement to restrict the CSA checks to certain hosts only.
+ #
+ # require verify = csa
+ #############################################################################
+
+
+ # Accept if the address is in a domain for which we are an incoming relay,
+ # but again, only if the recipient can be verified.
+
+ accept
+ domains = +relay_to_domains
+ endpass
+ verify = recipient
+
+
+ # At this point, the address has passed all the checks that have been
+ # configured, so we accept it unconditionally.
+
+ accept
projects / matthijs / servers / drsnuggles.git / blobdiff