[exim-config] / base.m4

### -*-m4-*-
###
### Basic settings for distorted.org.uk Exim configuration
###
### (c) 2012 Mark Wooding
###

###----- Licensing notice ---------------------------------------------------
###
### This program is free software; you can redistribute it and/or modify
### it under the terms of the GNU General Public License as published by
### the Free Software Foundation; either version 2 of the License, or
### (at your option) any later version.
###
### This program is distributed in the hope that it will be useful,
### but WITHOUT ANY WARRANTY; without even the implied warranty of
### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
### GNU General Public License for more details.
###
### You should have received a copy of the GNU General Public License
### along with this program; if not, write to the Free Software Foundation,
### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

###--------------------------------------------------------------------------
### Global settings.

SECTION(global, priv)m4_dnl
admin_groups = CONF_admin_groups
trusted_groups = CONF_trusted_groups
prod_requires_admin = false

SECTION(global, logging)m4_dnl
log_file_path = : syslog
log_selector = \
	+smtp_confirmation \
	+tls_peerdn
log_timezone = true
syslog_duplication = false
syslog_timestamp = false

SECTION(global, daemon)m4_dnl
local_interfaces = <; CONF_interfaces
extra_local_interfaces = <; 0.0.0.0 ; ::0

SECTION(global, resource)m4_dnl
deliver_queue_load_max = 8
queue_only_load = 12
smtp_accept_max = 16
smtp_accept_queue = 32
smtp_accept_reserve = 4
smtp_load_reserve = 10
smtp_reserve_hosts = +trusted

SECTION(global, policy)m4_dnl
host_lookup = *

SECTION(global, users)m4_dnl
gecos_name = $1
gecos_pattern = ([^,:]*)

SECTION(global, incoming)m4_dnl
rfc1413_hosts = *
rfc1413_query_timeout = 10s
received_header_text = Received: \
	${if def:sender_rcvhost \
	     {from $sender_rcvhost\n\t} \
	     {${if def:sender_ident \
		   {from ${quote_local_part:$sender_ident} }}}}\
	by $primary_hostname \
	(Exim $version_number)\
	${if def:tls_cipher {\n\t} { }}\
	${if def:received_protocol \
	     {with $received_protocol \
	      ${if def:tls_cipher {(cipher=$tls_cipher)}}}}\n\t\
	${if def:sender_address \
	     {(envelope-from $sender_address\
	      ${if def:authenticated_id \
		   {; auth=${quote_local_part:$authenticated_id}} \
		   {${if and {{def:authenticated_sender} \
			      {match_address{$authenticated_sender} \
					    {*@CONF_master_domain}}} \
			 {; auth=${quote_local_part:\
				    ${local_part:\
				      $authenticated_sender}}}}}})\n\t}}\
	id $message_exim_id\
	${if def:received_for {\n\tfor $received_for}}

SECTION(global, smtp)m4_dnl
smtp_return_error_details = true
accept_8bitmime = true
chunking_advertise_hosts =

SECTION(global, env)m4_dnl
keep_environment =

SECTION(global, process)m4_dnl
extract_addresses_remove_arguments = false
headers_charset = utf-8
qualify_domain = CONF_master_domain
untrusted_set_sender = *
local_from_check = false
local_sender_retain = true

SECTION(global, bounce)m4_dnl
delay_warning = 1h : 24h : 2d

SECTION(global, tls)m4_dnl
tls_certificate = CONF_sysconf_dir/server.certlist
tls_privatekey = CONF_sysconf_dir/server.key
tls_advertise_hosts = ${if exists {CONF_sysconf_dir/server.key} {*}{}}
tls_dhparam = CONF_ca_dir/dh-param-2048.pem
tls_require_ciphers = ${if or {{={$received_port}{CONF_submission_port}} \
			       {match_ip {$sender_host_address}{+trusted}}} \
			   {CONF_good_ciphers} \
			   {CONF_acceptable_ciphers}}
tls_verify_certificates = CONF_ca_dir/ca.cert
tls_verify_hosts = ${if eq{$acl_c_mode}{submission} {} {+allnets}}

DIVERT(null)
###--------------------------------------------------------------------------
### Access control lists.

SECTION(global, acl-after)
SECTION(global, acl)m4_dnl
acl_smtp_helo = helo
SECTION(acl, misc)m4_dnl
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 = \
			${if and {{match_ip {$sender_host_address} \
					    {<; 127.0.0.0/8 ; ::1}} \
				  {match_domain {$sender_helo_name} \
						{localhost : +thishost}}}}
		!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
		 set acl_m_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.  Only don't bother if the client has authenticated
	## successfully for submission (because we can't expect mobile
	## clients to be properly set up knowing their names), or it's one of
	## our own satellites (because they're either properly set up anyway,
	## or satellites using us as a smarthost).
	warn	 condition = $acl_c_helo_warning
		!condition = ${if eq{$acl_c_mode}{submission}}
		!hosts = +allnets
		 WARNING_HEADER(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 = :

	## Ensure that the sender looks valid.
	require	 acl = mail_check_sender

	## If this is directly from a client then hack on it for a while.
	warn	 condition = ${if eq{$acl_c_mode}{submission}}
		 control = submission/sender_retain

	## 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

SECTION(acl, misc)m4_dnl
mail_check_sender:

	## See whether there's a special exception for this sender domain.
	accept	 senders = ${LOOKUP_DOMAIN($sender_address_domain,
			     {KV(senders, {$value}{})},
			     {})}

	## Ensure that the sender is routable.  This is important to prevent
	## undeliverable bounces.
	require	 message = Invalid sender; \
			($sender_verify_failure; $acl_verify_message)
		 verify = sender

	## We're good, then.
	accept

SECTION(global, acl)m4_dnl
acl_smtp_connect = connect
SECTION(acl, connect)m4_dnl
connect:
SECTION(acl, connect-tail)m4_dnl
	## Configure variables according to the submission mode.
	warn	 acl = check_submission

	## Done.
	accept

check_submission:
	## See whether this message needs hacking on.
	accept	!hosts = +thishost
		!condition = ${if ={$received_port}{CONF_submission_port}}
		 set acl_c_mode = relay

	## Remember to apply submission controls.
	warn	 set acl_c_mode = submission

	## Done.
	accept

SECTION(global, acl)m4_dnl
acl_smtp_rcpt = rcpt
SECTION(acl, rcpt)m4_dnl
rcpt:

	## Reject if the client isn't allowed to relay and the recipient
	## isn't in one of our known domains.
	require	 message = Relaying not permitted
		 acl = check_relay

	## Ensure that the recipient is routable.
	require	 message = Invalid recipient \
			($recipient_verify_failure; $acl_verify_message)
		 verify = recipient

SECTION(acl, misc)m4_dnl
check_relay:
	## Accept either if the client is allowed to relay through us, or if
	## we're the correct place to send this mail.

	## Known clients and authenticated users are OK.
	accept	 hosts = CONF_relay_clients
	accept	 authenticated = *

	## Known domains are OK.
	accept	 domains = +public

	## Finally, domains in our table are OK, unless they say they aren't.
	accept	 domains = \
		 ${if exists{CONF_sysconf_dir/domains.conf} \
		     {partial0-lsearch;	CONF_sysconf_dir/domains.conf}}
		 condition = DOMKV(service, {$value}{true})

	## Nope, that's not allowed.
	deny

SECTION(acl, rcpt-tail)m4_dnl
	## Everything checks out OK: let this one go through.
	accept

SECTION(global, acl)m4_dnl
acl_smtp_data = data
SECTION(acl, data)m4_dnl
data:
	## Don't accept messages with overly-long lines.
	deny	 message = line length exceeds SMTP permitted maximum: \
			$max_received_linelength > 998
		 condition = ${if >{$max_received_linelength}{998}}

SECTION(acl, data-tail)m4_dnl
	accept

SECTION(global, acl)m4_dnl
acl_smtp_expn = expn_vrfy
acl_smtp_vrfy = expn_vrfy
SECTION(acl, misc)m4_dnl
expn_vrfy:
	accept	 hosts = +trusted
	deny	 message = Suck it and see

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 = +thishost
		!authenticated = *
		 condition = ${if def:sender_ident}
		 set acl_c_user = $sender_ident

	## User must be authenticated by now.
	deny	 message = Sender not authenticated
		 condition = ${if !def:acl_c_user}

	## Set the per-message authentication flag, since we now know that
	## there's a sensible value.
	warn	 set acl_m_user = $acl_c_user

	## All done.
	accept

DIVERT(null)
###--------------------------------------------------------------------------
### Common options for forwarding routers.

## We're pretty permissive here.
m4_define(<:FILTER_BASE:>,
	<:driver = redirect
	modemask = 002
	check_owner = false
	check_group = false
	allow_filter = true
	allow_defer = true
	allow_fail = true
	forbid_blackhole = false
	check_ancestor = true:>)

## Common options for forwarding routers at verification time.
m4_define(<:FILTER_VERIFY:>,
	<:verify_only = true
	user = CONF_filter_user
	forbid_filter_dlfunc = true
	forbid_filter_logwrite = true
	forbid_filter_perl = true
	forbid_filter_readsocket = true
	forbid_filter_run = true
	file_transport = dummy
	directory_transport = dummy
	pipe_transport = dummy
	reply_transport = dummy:>)

## Transports for redirection filters.
m4_define(<:FILTER_TRANSPORTS:>,
	<:file_transport = mailbox
	directory_transport = maildir
	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)
###--------------------------------------------------------------------------
### Common routers.

SECTION(routers, alias)m4_dnl
## Look up the local part in the address map.
alias:
	driver = redirect
	allow_fail = true
	allow_defer = true
	user = CONF_filter_user
	FILTER_TRANSPORTS
	local_parts = nwildlsearch; CONF_alias_file
	data = ${expand:$local_part_data}
SECTION(routers, alias-opts)m4_dnl

DIVERT(null)
###--------------------------------------------------------------------------
### Some standard transports.

m4_define(<:USER_DELIVERY:>,
	<:delivery_date_add = true
	envelope_to_add = true
	return_path_add = true:>)

m4_define(<:APPLY_HEADER_CHANGES:>,
	<:headers_add = m4_ifelse(<:$1:>, <::>,
		<:$acl_m_hdradd:>,
		<:${if def:acl_m_hdradd{$acl_m_hdradd\n}}\
		$1:>)
	headers_remove = m4_ifelse(<:$2:>, <::>,
		<:$acl_m_hdrrm:>,
		<:${if def:acl_m_hdrrm{$acl_m_hdrrm:}}\
		$2:>):>)

m4_define(<:SMTP_DELIVERY:>,
	<:## Prevent sending messages with overly long lines.  The use of
	## `message_size_limit' here is somewhat misleading.
	message_size_limit = ${if >{$max_received_linelength}{998}{1}{0}}:>)

SECTION(transports)m4_dnl
## A standard transport for remote delivery.  By default, try to do TLS, and
## don't worry too much if it's not very secure: the alternative is sending
## in plaintext anyway.  But all of this can be overridden from the
## `domains.conf' file.  Annoyingly, the `tls_dh_min_bits' setting isn't
## expanded before use, so we can't set it the obvious way.  Instead, encode
## it into the transport name.  This is very unpleasant, of course.
smtp:
	driver = smtp
	APPLY_HEADER_CHANGES
	tls_require_ciphers = CONF_acceptable_ciphers
	tls_dh_min_bits = 508
	tls_tempfail_tryclear = true

m4_define(<:SMTP_TRANS_DHBITS:>,
	<:driver = smtp
	SMTP_DELIVERY
	APPLY_HEADER_CHANGES
	hosts_try_auth = *
	hosts_require_tls = DOMKV(tls-peer-ca, {*}{})
	hosts_require_auth = \
		${if bool {DOMKV(require-auth, {$value}{false})} {*}{}}
	tls_certificate = DOMKV(tls-certificate, {${expand:$value}}fail)
	tls_privatekey = DOMKV(tls-private-key, {${expand:$value}}fail)
	tls_verify_certificates = DOMKV(tls-peer-ca, {${expand:$value}}fail)
	tls_require_ciphers = \
		DOMKV(tls-ciphers,
		      {${extract {${expand:$value}} \
				 { good = CONF_good_ciphers \
				   any = CONF_acceptable_ciphers } \
				 {$value} \
				 {${expand:$value}}}} \
		      {CONF_acceptable_ciphers})
	tls_dh_min_bits = $1
	tls_tempfail_tryclear = true:>)m4_dnl
smtp_dhbits_512:
	SMTP_TRANS_DHBITS(508)
smtp_dhbits_768:
	SMTP_TRANS_DHBITS(764)
smtp_dhbits_1024:
	SMTP_TRANS_DHBITS(1020)
smtp_dhbits_2048:
	SMTP_TRANS_DHBITS(2044)

## Transport to a local SMTP server; use TLS and perform client
## authentication.
smtp_local:
	driver = smtp
	SMTP_DELIVERY
	APPLY_HEADER_CHANGES
	hosts_require_tls = *
	tls_certificate = CONF_sysconf_dir/client.certlist
	tls_privatekey = CONF_sysconf_dir/client.key
	tls_verify_certificates = CONF_ca_dir/ca.cert
	tls_require_ciphers = CONF_good_ciphers
	tls_dh_min_bits = 2046
	tls_tempfail_tryclear = false
	authenticated_sender_force = true
	authenticated_sender = \
		${if def:acl_m_user {$acl_m_user@CONF_master_domain} \
		     {${if def:authenticated_sender {$authenticated_sender} \
			   fail}}}

## A standard transport for local delivery.
deliver:
	driver = appendfile
	APPLY_HEADER_CHANGES
	file = /var/mail/$local_part
	group = mail
	mode = 0600
	mode_fail_narrower = false
	USER_DELIVERY

## Transports for user filters.
mailbox:
	driver = appendfile
	APPLY_HEADER_CHANGES
	initgroups = true
	USER_DELIVERY

maildir:
	driver = appendfile
	APPLY_HEADER_CHANGES
	maildir_format = true
	initgroups = true
	USER_DELIVERY

pipe:
	driver = pipe
	APPLY_HEADER_CHANGES
	path = ${if and {{def:home} {exists{$home/bin}}} {$home/bin:} {}}\
		/usr/local/bin:/usr/local/sbin:\
		/usr/bin:/usr/sbin:/bin:/sbin
	initgroups = true
	umask = 002
	return_fail_output = true
	log_output = true

## A special dummy transport for use during address verification.
dummy:
	driver = appendfile
	file = /dev/null

DIVERT(null)
###--------------------------------------------------------------------------
### Retry configuration.

SECTION(retry, default)m4_dnl
## Default.
*					* \
	F,2h,15m; G,16h,2h,1.5; F,4d,6h

DIVERT(null)
###----- That's all, folks --------------------------------------------------
Commit	Line	Data
185b5456 MW	1	### --m4--
	2	###
	3	### Basic settings for distorted.org.uk Exim configuration
	4	###
	5	### (c) 2012 Mark Wooding
	6	###
	7
	8	###----- Licensing notice ---------------------------------------------------
	9	###
	10	### This program is free software; you can redistribute it and/or modify
	11	### it under the terms of the GNU General Public License as published by
	12	### the Free Software Foundation; either version 2 of the License, or
	13	### (at your option) any later version.
	14	###
	15	### This program is distributed in the hope that it will be useful,
	16	### but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	### GNU General Public License for more details.
	19	###
	20	### You should have received a copy of the GNU General Public License
	21	### along with this program; if not, write to the Free Software Foundation,
	22	### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	23
	24	###--------------------------------------------------------------------------
	25	### Global settings.
	26
	27	SECTION(global, priv)m4_dnl
b1d083dd	28	admin_groups = CONF_admin_groups
e8fc7835	29	trusted_groups = CONF_trusted_groups
185b5456 MW	30	prod_requires_admin = false
	31
	32	SECTION(global, logging)m4_dnl
	33	log_file_path = : syslog
	34	log_selector = \
	35	+smtp_confirmation \
	36	+tls_peerdn
	37	log_timezone = true
	38	syslog_duplication = false
	39	syslog_timestamp = false
	40
	41	SECTION(global, daemon)m4_dnl
	42	local_interfaces = <; CONF_interfaces
ad4e4191	43	extra_local_interfaces = <; 0.0.0.0 ; ::0
185b5456 MW	44
	45	SECTION(global, resource)m4_dnl
	46	deliver_queue_load_max = 8
	47	queue_only_load = 12
	48	smtp_accept_max = 16
	49	smtp_accept_queue = 32
	50	smtp_accept_reserve = 4
	51	smtp_load_reserve = 10
	52	smtp_reserve_hosts = +trusted
	53
	54	SECTION(global, policy)m4_dnl
	55	host_lookup = *
	56
	57	SECTION(global, users)m4_dnl
	58	gecos_name = $1
	59	gecos_pattern = ([^,:]*)
	60
	61	SECTION(global, incoming)m4_dnl
ceb81bc4 MW	62	rfc1413_hosts = *
ceb81bc4 MW	63	rfc1413_query_timeout = 10s
185b5456	64	received_header_text = Received: \
2cf9db84	65	${if def:sender_rcvhost \
9384ef4f	66	{from $sender_rcvhost\n\t} \
2cf9db84 MW	67	{${if def:sender_ident \
2cf9db84 MW	68	{from ${quote_local_part:$sender_ident} }}}}\
185b5456	69	by $primary_hostname \
b92689d6 MW	70	(Exim $version_number)\
b92689d6 MW	71	${if def:tls_cipher {\n\t} { }}\
185b5456 MW	72	${if def:received_protocol \
185b5456 MW	73	{with $received_protocol \
b92689d6	74	${if def:tls_cipher {(cipher=$tls_cipher)}}}}\n\t\
185b5456	75	${if def:sender_address \
43e6fc69	76	{(envelope-from $sender_address\
185b5456	77	${if def:authenticated_id \
8fa6a843 MW	78	{; auth=${quote_local_part:$authenticated_id}} \
	79	{${if and {{def:authenticated_sender} \
	80	{match_address{$authenticated_sender} \
	81	{*@CONF_master_domain}}} \
	82	{; auth=${quote_local_part:\
	83	${local_part:\
	84	$authenticated_sender}}}}}})\n\t}}\
185b5456 MW	85	id $message_exim_id\
	86	${if def:received_for {\n\tfor $received_for}}
	87
	88	SECTION(global, smtp)m4_dnl
	89	smtp_return_error_details = true
	90	accept_8bitmime = true
e3c9c427	91	chunking_advertise_hosts =
185b5456	92
5918499b MW	93	SECTION(global, env)m4_dnl
	94	keep_environment =
	95
185b5456 MW	96	SECTION(global, process)m4_dnl
	97	extract_addresses_remove_arguments = false
	98	headers_charset = utf-8
	99	qualify_domain = CONF_master_domain
12d3b444	100	untrusted_set_sender = *
75c86bd1 MW	101	local_from_check = false
75c86bd1 MW	102	local_sender_retain = true
185b5456 MW	103
	104	SECTION(global, bounce)m4_dnl
	105	delay_warning = 1h : 24h : 2d
	106
6aae076f	107	SECTION(global, tls)m4_dnl
163774f0	108	tls_certificate = CONF_sysconf_dir/server.certlist
6aae076f MW	109	tls_privatekey = CONF_sysconf_dir/server.key
	110	tls_advertise_hosts = ${if exists {CONF_sysconf_dir/server.key} {*}{}}
	111	tls_dhparam = CONF_ca_dir/dh-param-2048.pem
	112	tls_require_ciphers = ${if or {{={$received_port}{CONF_submission_port}} \
	113	{match_ip {$sender_host_address}{+trusted}}} \
	114	{CONF_good_ciphers} \
	115	{CONF_acceptable_ciphers}}
	116	tls_verify_certificates = CONF_ca_dir/ca.cert
	117	tls_verify_hosts = ${if eq{$acl_c_mode}{submission} {} {+allnets}}
	118
185b5456 MW	119	DIVERT(null)
	120	###--------------------------------------------------------------------------
	121	### Access control lists.
	122
	123	SECTION(global, acl-after)
	124	SECTION(global, acl)m4_dnl
	125	acl_smtp_helo = helo
	126	SECTION(acl, misc)m4_dnl
	127	helo:
fe8f2338 MW	128	## Check that the caller's claimed identity is actually plausible.
	129	## This seems like it's a fairly effective filter on spamminess, but
	130	## it's too blunt a tool. Rather than reject, add a warning header.
	131	## Only we can't do this the easy way, so save it up for use in MAIL.
	132	## Also, we're liable to get a subsequent HELO (e.g., after STARTTLS)
	133	## and we should only care about the most recent one.
	134	warn set acl_c_helo_warning = false
4ff4ad42 MW	135	!condition = \
	136	${if and {{match_ip {$sender_host_address} \
	137	{<; 127.0.0.0/8 ; ::1}} \
	138	{match_domain {$sender_helo_name} \
	139	{localhost : +thishost}}}}
fe8f2338 MW	140	!condition = \
	141	${if exists {CONF_sysconf_dir/helo.conf} \
	142	{${lookup {$sender_helo_name} \
	143	partial0-lsearch \
	144	{CONF_sysconf_dir/helo.conf} \
	145	{${if match_ip \
	146	{$sender_host_address} \
4587a704	147	{<; $value}}}}}}
fe8f2338 MW	148	!verify = helo
fe8f2338 MW	149	set acl_c_helo_warning = true
185b5456 MW	150
	151	accept
	152
284c9d7e MW	153	SECTION(global, acl)m4_dnl
	154	acl_not_smtp_start = not_smtp_start
	155	SECTION(acl, misc)m4_dnl
	156	not_smtp_start:
	157	## Record the user's name.
	158	warn set acl_c_user = $sender_ident
e9015968	159	set acl_m_user = $sender_ident
284c9d7e MW	160
	161	## Done.
	162	accept
	163
185b5456 MW	164	SECTION(global, acl)m4_dnl
	165	acl_smtp_mail = mail
	166	SECTION(acl, mail)m4_dnl
	167	mail:
	168
fe8f2338	169	## If we stashed a warning header about HELO from earlier, we should
2f0841ce MW	170	## add it now. Only don't bother if the client has authenticated
	171	## successfully for submission (because we can't expect mobile
	172	## clients to be properly set up knowing their names), or it's one of
	173	## our own satellites (because they're either properly set up anyway,
	174	## or satellites using us as a smarthost).
fe8f2338	175	warn condition = $acl_c_helo_warning
2f0841ce MW	176	!condition = ${if eq{$acl_c_mode}{submission}}
2f0841ce MW	177	!hosts = +allnets
61295d9c MW	178	WARNING_HEADER(BADHELO,
	179	<:Client's HELO doesn't match its IP address.\n\t\
	180	helo-name=$sender_helo_name \
	181	address=$sender_host_address:>)
fe8f2338	182
185b5456 MW	183	## Always allow the empty sender, so that we can receive bounces.
	184	accept senders = :
	185
5051a30f MW	186	## Ensure that the sender looks valid.
5051a30f MW	187	require acl = mail_check_sender
185b5456 MW	188
	189	## If this is directly from a client then hack on it for a while.
	190	warn condition = ${if eq{$acl_c_mode}{submission}}
12d3b444	191	control = submission/sender_retain
185b5456	192
284c9d7e MW	193	## Insist that a local client connect through TLS.
	194	deny message = Hosts within CONF_master_domain must use TLS
	195	!condition = ${if eq{$acl_c_mode}{submission}}
	196	hosts = +allnets
	197	!encrypted = *
	198
	199	## Check that a submitted message's sender address is allowable.
	200	require acl = mail_check_auth
	201
185b5456 MW	202	SECTION(acl, mail-tail)m4_dnl
	203	## And we're done.
	204	accept
	205
5051a30f MW	206	SECTION(acl, misc)m4_dnl
	207	mail_check_sender:
	208
	209	## See whether there's a special exception for this sender domain.
	210	accept senders = ${LOOKUP_DOMAIN($sender_address_domain,
	211	{KV(senders, {$value}{})},
	212	{})}
	213
	214	## Ensure that the sender is routable. This is important to prevent
	215	## undeliverable bounces.
	216	require message = Invalid sender; \
	217	($sender_verify_failure; $acl_verify_message)
	218	verify = sender
	219
	220	## We're good, then.
	221	accept
	222
185b5456 MW	223	SECTION(global, acl)m4_dnl
	224	acl_smtp_connect = connect
	225	SECTION(acl, connect)m4_dnl
	226	connect:
	227	SECTION(acl, connect-tail)m4_dnl
e12c9586	228	## Configure variables according to the submission mode.
185b5456	229	warn acl = check_submission
e12c9586 MW	230
e12c9586 MW	231	## Done.
185b5456 MW	232	accept
	233
	234	check_submission:
	235	## See whether this message needs hacking on.
4ff4ad42	236	accept !hosts = +thishost
185b5456 MW	237	!condition = ${if ={$received_port}{CONF_submission_port}}
	238	set acl_c_mode = relay
	239
	240	## Remember to apply submission controls.
	241	warn set acl_c_mode = submission
	242
	243	## Done.
	244	accept
	245
	246	SECTION(global, acl)m4_dnl
	247	acl_smtp_rcpt = rcpt
	248	SECTION(acl, rcpt)m4_dnl
	249	rcpt:
	250
	251	## Reject if the client isn't allowed to relay and the recipient
	252	## isn't in one of our known domains.
e4666f2d MW	253	require message = Relaying not permitted
e4666f2d MW	254	acl = check_relay
185b5456 MW	255
	256	## Ensure that the recipient is routable.
	257	require message = Invalid recipient \
	258	($recipient_verify_failure; $acl_verify_message)
	259	verify = recipient
	260
e4666f2d MW	261	SECTION(acl, misc)m4_dnl
	262	check_relay:
	263	## Accept either if the client is allowed to relay through us, or if
	264	## we're the correct place to send this mail.
	265
	266	## Known clients and authenticated users are OK.
a0375fd9 MW	267	accept hosts = CONF_relay_clients
a0375fd9 MW	268	accept authenticated = *
e4666f2d MW	269
e4666f2d MW	270	## Known domains are OK.
a0375fd9	271	accept domains = +public
e4666f2d MW	272
e4666f2d MW	273	## Finally, domains in our table are OK, unless they say they aren't.
a0375fd9 MW	274	accept domains = \
a0375fd9 MW	275	${if exists{CONF_sysconf_dir/domains.conf} \
e4666f2d	276	{partial0-lsearch; CONF_sysconf_dir/domains.conf}}
a0375fd9	277	condition = DOMKV(service, {$value}{true})
e4666f2d MW	278
	279	## Nope, that's not allowed.
	280	deny
	281
185b5456 MW	282	SECTION(acl, rcpt-tail)m4_dnl
	283	## Everything checks out OK: let this one go through.
	284	accept
	285
	286	SECTION(global, acl)m4_dnl
	287	acl_smtp_data = data
	288	SECTION(acl, data)m4_dnl
	289	data:
5d2f8b65 MW	290	## Don't accept messages with overly-long lines.
	291	deny message = line length exceeds SMTP permitted maximum: \
	292	$max_received_linelength > 998
	293	condition = ${if >{$max_received_linelength}{998}}
185b5456 MW	294
	295	SECTION(acl, data-tail)m4_dnl
	296	accept
	297
	298	SECTION(global, acl)m4_dnl
	299	acl_smtp_expn = expn_vrfy
	300	acl_smtp_vrfy = expn_vrfy
e4fe8925	301	SECTION(acl, misc)m4_dnl
185b5456 MW	302	expn_vrfy:
	303	accept hosts = +trusted
	304	deny message = Suck it and see
	305
	306	DIVERT(null)
	307	###--------------------------------------------------------------------------
284c9d7e MW	308	### Verification of sender address.
	309
	310	SECTION(acl, misc)m4_dnl
	311	mail_check_auth:
	312
	313	## If this isn't a submission then it doesn't need checking.
	314	accept condition = ${if !eq{$acl_c_mode}{submission}}
	315
	316	## If the caller hasn't formally authenticated, but this is a
	317	## loopback connection, then we can trust identd to tell us the right
	318	## answer. So we should stash the right name somewhere consistent.
	319	warn set acl_c_user = $authenticated_id
4ff4ad42	320	hosts = +thishost
284c9d7e	321	!authenticated = *
ff4c943d	322	condition = ${if def:sender_ident}
284c9d7e MW	323	set acl_c_user = $sender_ident
284c9d7e MW	324
ff4c943d	325	## User must be authenticated by now.
284c9d7e	326	deny message = Sender not authenticated
ff4c943d	327	condition = ${if !def:acl_c_user}
284c9d7e	328
e9015968 MW	329	## Set the per-message authentication flag, since we now know that
	330	## there's a sensible value.
	331	warn set acl_m_user = $acl_c_user
	332
284c9d7e MW	333	## All done.
	334	accept
	335
	336	DIVERT(null)
	337	###--------------------------------------------------------------------------
185b5456 MW	338	### Common options for forwarding routers.
	339
	340	## We're pretty permissive here.
	341	m4_define(<:FILTER_BASE:>,
	342	<:driver = redirect
	343	modemask = 002
	344	check_owner = false
	345	check_group = false
	346	allow_filter = true
	347	allow_defer = true
	348	allow_fail = true
	349	forbid_blackhole = false
	350	check_ancestor = true:>)
	351
	352	## Common options for forwarding routers at verification time.
	353	m4_define(<:FILTER_VERIFY:>,
	354	<:verify_only = true
	355	user = CONF_filter_user
	356	forbid_filter_dlfunc = true
	357	forbid_filter_logwrite = true
	358	forbid_filter_perl = true
	359	forbid_filter_readsocket = true
	360	forbid_filter_run = true
	361	file_transport = dummy
	362	directory_transport = dummy
	363	pipe_transport = dummy
	364	reply_transport = dummy:>)
	365
	366	## Transports for redirection filters.
	367	m4_define(<:FILTER_TRANSPORTS:>,
7ab75d6f	368	<:file_transport = mailbox
185b5456 MW	369	directory_transport = maildir
	370	pipe_transport = pipe
	371	reply_transport = reply:>)
	372
7ab75d6f MW	373	m4_define(<:FILTER_ROUTER:>,
	374	<:$1_vrf:
	375	$2
	376	FILTER_VERIFY<::>$3
	377	$1:
	378	$2
	379	verify = no
	380	FILTER_TRANSPORTS<::>$4:>)
	381
185b5456 MW	382	DIVERT(null)
185b5456 MW	383	###--------------------------------------------------------------------------
3e031e77 MW	384	### Common routers.
	385
	386	SECTION(routers, alias)m4_dnl
	387	## Look up the local part in the address map.
	388	alias:
	389	driver = redirect
	390	allow_fail = true
	391	allow_defer = true
	392	user = CONF_filter_user
	393	FILTER_TRANSPORTS
	394	local_parts = nwildlsearch; CONF_alias_file
	395	data = ${expand:$local_part_data}
	396	SECTION(routers, alias-opts)m4_dnl
	397
	398	DIVERT(null)
	399	###--------------------------------------------------------------------------
185b5456 MW	400	### Some standard transports.
	401
	402	m4_define(<:USER_DELIVERY:>,
	403	<:delivery_date_add = true
	404	envelope_to_add = true
	405	return_path_add = true:>)
	406
1e5ccd7c MW	407	m4_define(<:APPLY_HEADER_CHANGES:>,
	408	<:headers_add = m4_ifelse(<:$1:>, <::>,
	409	<:$acl_m_hdradd:>,
	410	<:${if def:acl_m_hdradd{$acl_m_hdradd\n}}\
	411	$1:>)
	412	headers_remove = m4_ifelse(<:$2:>, <::>,
	413	<:$acl_m_hdrrm:>,
	414	<:${if def:acl_m_hdrrm{$acl_m_hdrrm:}}\
	415	$2:>):>)
	416
5d2f8b65 MW	417	m4_define(<:SMTP_DELIVERY:>,
	418	<:## Prevent sending messages with overly long lines. The use of
	419	## `message_size_limit' here is somewhat misleading.
	420	message_size_limit = ${if >{$max_received_linelength}{998}{1}{0}}:>)
	421
185b5456	422	SECTION(transports)m4_dnl
fa5a92c6 MW	423	## A standard transport for remote delivery. By default, try to do TLS, and
	424	## don't worry too much if it's not very secure: the alternative is sending
	425	## in plaintext anyway. But all of this can be overridden from the
beb15dae MW	426	## `domains.conf' file. Annoyingly, the `tls_dh_min_bits' setting isn't
	427	## expanded before use, so we can't set it the obvious way. Instead, encode
	428	## it into the transport name. This is very unpleasant, of course.
534d411b MW	429	smtp:
534d411b MW	430	driver = smtp
1e5ccd7c	431	APPLY_HEADER_CHANGES
534d411b	432	tls_require_ciphers = CONF_acceptable_ciphers
7b50997d	433	tls_dh_min_bits = 508
534d411b MW	434	tls_tempfail_tryclear = true
534d411b MW	435
beb15dae MW	436	m4_define(<:SMTP_TRANS_DHBITS:>,
beb15dae MW	437	<:driver = smtp
5d2f8b65	438	SMTP_DELIVERY
1e5ccd7c	439	APPLY_HEADER_CHANGES
ae9744ce	440	hosts_try_auth = *
fa5a92c6	441	hosts_require_tls = DOMKV(tls-peer-ca, {*}{})
ae9744ce MW	442	hosts_require_auth = \
ae9744ce MW	443	${if bool {DOMKV(require-auth, {$value}{false})} {*}{}}
fa5a92c6 MW	444	tls_certificate = DOMKV(tls-certificate, {${expand:$value}}fail)
	445	tls_privatekey = DOMKV(tls-private-key, {${expand:$value}}fail)
	446	tls_verify_certificates = DOMKV(tls-peer-ca, {${expand:$value}}fail)
	447	tls_require_ciphers = \
	448	DOMKV(tls-ciphers,
	449	{${extract {${expand:$value}} \
	450	{ good = CONF_good_ciphers \
	451	any = CONF_acceptable_ciphers } \
	452	{$value} \
	453	{${expand:$value}}}} \
	454	{CONF_acceptable_ciphers})
beb15dae MW	455	tls_dh_min_bits = $1
beb15dae MW	456	tls_tempfail_tryclear = true:>)m4_dnl
7b50997d MW	457	smtp_dhbits_512:
	458	SMTP_TRANS_DHBITS(508)
	459	smtp_dhbits_768:
	460	SMTP_TRANS_DHBITS(764)
beb15dae MW	461	smtp_dhbits_1024:
	462	SMTP_TRANS_DHBITS(1020)
	463	smtp_dhbits_2048:
7b50997d	464	SMTP_TRANS_DHBITS(2044)
185b5456 MW	465
	466	## Transport to a local SMTP server; use TLS and perform client
	467	## authentication.
	468	smtp_local:
	469	driver = smtp
5d2f8b65	470	SMTP_DELIVERY
1e5ccd7c	471	APPLY_HEADER_CHANGES
185b5456	472	hosts_require_tls = *
163774f0	473	tls_certificate = CONF_sysconf_dir/client.certlist
185b5456 MW	474	tls_privatekey = CONF_sysconf_dir/client.key
	475	tls_verify_certificates = CONF_ca_dir/ca.cert
	476	tls_require_ciphers = CONF_good_ciphers
b6d74252	477	tls_dh_min_bits = 2046
185b5456	478	tls_tempfail_tryclear = false
10c331d7 MW	479	authenticated_sender_force = true
	480	authenticated_sender = \
	481	${if def:acl_m_user {$acl_m_user@CONF_master_domain} \
	482	{${if def:authenticated_sender {$authenticated_sender} \
	483	fail}}}
185b5456 MW	484
	485	## A standard transport for local delivery.
	486	deliver:
	487	driver = appendfile
1e5ccd7c	488	APPLY_HEADER_CHANGES
185b5456	489	file = /var/mail/$local_part
8f6af4ae MW	490	group = mail
	491	mode = 0600
	492	mode_fail_narrower = false
185b5456 MW	493	USER_DELIVERY
	494
	495	## Transports for user filters.
	496	mailbox:
	497	driver = appendfile
1e5ccd7c	498	APPLY_HEADER_CHANGES
8f6af4ae	499	initgroups = true
185b5456 MW	500	USER_DELIVERY
	501
	502	maildir:
	503	driver = appendfile
1e5ccd7c	504	APPLY_HEADER_CHANGES
185b5456	505	maildir_format = true
8f6af4ae	506	initgroups = true
185b5456 MW	507	USER_DELIVERY
	508
	509	pipe:
	510	driver = pipe
1e5ccd7c	511	APPLY_HEADER_CHANGES
8f6af4ae MW	512	path = ${if and {{def:home} {exists{$home/bin}}} {$home/bin:} {}}\
	513	/usr/local/bin:/usr/local/sbin:\
	514	/usr/bin:/usr/sbin:/bin:/sbin
	515	initgroups = true
	516	umask = 002
	517	return_fail_output = true
	518	log_output = true
185b5456 MW	519
	520	## A special dummy transport for use during address verification.
	521	dummy:
	522	driver = appendfile
	523	file = /dev/null
	524
	525	DIVERT(null)
	526	###--------------------------------------------------------------------------
	527	### Retry configuration.
	528
	529	SECTION(retry, default)m4_dnl
	530	## Default.
	531	* * \
	532	F,2h,15m; G,16h,2h,1.5; F,4d,6h
	533
	534	DIVERT(null)
	535	###----- That's all, folks --------------------------------------------------