SECTION(global, incoming)m4_dnl
received_header_text = Received: \
- ${if def:sender_rcvhost {from $sender_rcvhost\n\t} \
+ ${if def:sender_rcvhost \
+ {from $sender_rcvhost\n\t} \
{${if def:sender_ident \
- {from ${quote_local_part:$sender_ident} }}\
- ${if def:sender_helo_name \
- {(helo=$sender_helo_name)\n\t}}}}\
+ {from ${quote_local_part:$sender_ident} }}}}\
by $primary_hostname \
(Exim $version_number)\
${if def:tls_cipher {\n\t} { }}\
{with $received_protocol \
${if def:tls_cipher {(cipher=$tls_cipher)}}}}\n\t\
${if def:sender_address \
- {(envelope-from <$sender_address>\
+ {(envelope-from $sender_address\
${if def:authenticated_id \
{; auth=$authenticated_id}})\n\t}}\
id $message_exim_id\
acl_smtp_helo = helo
SECTION(acl, misc)m4_dnl
helo:
- require message = The other one has bells on
- verify = helo
+ ## Check that the caller's claimed identity is actually plausible.
+ ## This seems like it's a fairly effective filter on spamminess, but
+ ## it's too blunt a tool. Rather than reject, add a warning header.
+ ## Only we can't do this the easy way, so save it up for use in MAIL.
+ ## Also, we're liable to get a subsequent HELO (e.g., after STARTTLS)
+ ## and we should only care about the most recent one.
+ warn set acl_c_helo_warning = false
+ !condition = \
+ ${if exists {CONF_sysconf_dir/helo.conf} \
+ {${lookup {$sender_helo_name} \
+ partial0-lsearch \
+ {CONF_sysconf_dir/helo.conf} \
+ {${if match_ip \
+ {$sender_host_address} \
+ {$value}}}}}}
+ !verify = helo
+ set acl_c_helo_warning = true
accept
SECTION(global, acl)m4_dnl
+acl_not_smtp_start = not_smtp_start
+SECTION(acl, misc)m4_dnl
+not_smtp_start:
+ ## Record the user's name.
+ warn set acl_c_user = $sender_ident
+
+ ## Done.
+ accept
+
+SECTION(global, acl)m4_dnl
acl_smtp_mail = mail
SECTION(acl, mail)m4_dnl
mail:
+ ## If we stashed a warning header about HELO from earlier, we should
+ ## add it now.
+ warn condition = $acl_c_helo_warning
+ add_header = :after_received:X-Distorted-Warning: \
+ BADHELO \
+ Client's HELO doesn't match its IP address.\n\t\
+ HELO name=$sender_helo_name, \
+ address=$sender_host_address
+
## Always allow the empty sender, so that we can receive bounces.
accept senders = :
warn condition = ${if eq{$acl_c_mode}{submission}}
control = submission
+ ## Insist that a local client connect through TLS.
+ deny message = Hosts within CONF_master_domain must use TLS
+ !condition = ${if eq{$acl_c_mode}{submission}}
+ hosts = +allnets
+ !encrypted = *
+
+ ## Check that a submitted message's sender address is allowable.
+ require acl = mail_check_auth
+
SECTION(acl, mail-tail)m4_dnl
## And we're done.
accept
DIVERT(null)
###--------------------------------------------------------------------------
+### Verification of sender address.
+
+SECTION(acl, misc)m4_dnl
+mail_check_auth:
+
+ ## If this isn't a submission then it doesn't need checking.
+ accept condition = ${if !eq{$acl_c_mode}{submission}}
+
+ ## If the caller hasn't formally authenticated, but this is a
+ ## loopback connection, then we can trust identd to tell us the right
+ ## answer. So we should stash the right name somewhere consistent.
+ warn set acl_c_user = $authenticated_id
+ hosts = +localnet
+ !authenticated = *
+ set acl_c_user = $sender_ident
+
+ ## User must be authenticated.
+ deny message = Sender not authenticated
+ !hosts = +localnet
+ !authenticated = *
+
+ ## Make sure that the local part is one that the authenticated sender
+ ## is allowed to claim.
+ deny message = Sender address forbidden to calling user
+ !condition = ${LOOKUP_DOMAIN($sender_address_domain,
+ {${if and {{match_local_part \
+ {$acl_c_user} \
+ {+dom_users}} \
+ {match_local_part \
+ {$sender_address_local_part} \
+ {+dom_locals}}}}},
+ {${if and {{match_local_part \
+ {$sender_address_local_part} \
+ {+user_extaddr}} \
+ {or {{eq {$sender_address_domain} \
+ {}} \
+ {match_domain \
+ {$sender_address_domain} \
+ {+public}}}}}}})}
+
+ ## All done.
+ accept
+
+DIVERT(null)
+###--------------------------------------------------------------------------
### Common options for forwarding routers.
## We're pretty permissive here.
pipe_transport = pipe
reply_transport = reply:>)
+m4_define(<:FILTER_ROUTER:>,
+<:$1_vrf:
+ $2
+ FILTER_VERIFY<::>$3
+$1:
+ $2
+ verify = no
+ FILTER_TRANSPORTS<::>$4:>)
+
DIVERT(null)
###--------------------------------------------------------------------------
### Some standard transports.
~mdw / exim-config / blobdiff