[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
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\
	      ${if def:authenticated_id \
		   {; auth=$authenticated_id}})\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

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

	## 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:

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}

	## 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:>):>)

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 = 1020
	tls_tempfail_tryclear = true

m4_define(<:SMTP_TRANS_DHBITS:>,
	<:driver = smtp
	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_1024:
	SMTP_TRANS_DHBITS(1020)
smtp_dhbits_2048:
	SMTP_TRANS_DHBITS(2046)

## Transport to a local SMTP server; use TLS and perform client
## authentication.
smtp_local:
	driver = smtp
	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 = ${if def:authenticated_id \
				    {$authenticated_id@CONF_master_domain} \
				    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
	62	received_header_text = Received: \
2cf9db84	63	${if def:sender_rcvhost \
9384ef4f	64	{from $sender_rcvhost\n\t} \
2cf9db84 MW	65	{${if def:sender_ident \
2cf9db84 MW	66	{from ${quote_local_part:$sender_ident} }}}}\
185b5456	67	by $primary_hostname \
b92689d6 MW	68	(Exim $version_number)\
b92689d6 MW	69	${if def:tls_cipher {\n\t} { }}\
185b5456 MW	70	${if def:received_protocol \
185b5456 MW	71	{with $received_protocol \
b92689d6	72	${if def:tls_cipher {(cipher=$tls_cipher)}}}}\n\t\
185b5456	73	${if def:sender_address \
43e6fc69	74	{(envelope-from $sender_address\
185b5456 MW	75	${if def:authenticated_id \
	76	{; auth=$authenticated_id}})\n\t}}\
	77	id $message_exim_id\
	78	${if def:received_for {\n\tfor $received_for}}
	79
	80	SECTION(global, smtp)m4_dnl
	81	smtp_return_error_details = true
	82	accept_8bitmime = true
	83
5918499b MW	84	SECTION(global, env)m4_dnl
	85	keep_environment =
	86
185b5456 MW	87	SECTION(global, process)m4_dnl
	88	extract_addresses_remove_arguments = false
	89	headers_charset = utf-8
	90	qualify_domain = CONF_master_domain
12d3b444	91	untrusted_set_sender = *
75c86bd1 MW	92	local_from_check = false
75c86bd1 MW	93	local_sender_retain = true
185b5456 MW	94
	95	SECTION(global, bounce)m4_dnl
	96	delay_warning = 1h : 24h : 2d
	97
6aae076f	98	SECTION(global, tls)m4_dnl
163774f0	99	tls_certificate = CONF_sysconf_dir/server.certlist
6aae076f MW	100	tls_privatekey = CONF_sysconf_dir/server.key
	101	tls_advertise_hosts = ${if exists {CONF_sysconf_dir/server.key} {*}{}}
	102	tls_dhparam = CONF_ca_dir/dh-param-2048.pem
	103	tls_require_ciphers = ${if or {{={$received_port}{CONF_submission_port}} \
	104	{match_ip {$sender_host_address}{+trusted}}} \
	105	{CONF_good_ciphers} \
	106	{CONF_acceptable_ciphers}}
	107	tls_verify_certificates = CONF_ca_dir/ca.cert
	108	tls_verify_hosts = ${if eq{$acl_c_mode}{submission} {} {+allnets}}
	109
185b5456 MW	110	DIVERT(null)
	111	###--------------------------------------------------------------------------
	112	### Access control lists.
	113
	114	SECTION(global, acl-after)
	115	SECTION(global, acl)m4_dnl
	116	acl_smtp_helo = helo
	117	SECTION(acl, misc)m4_dnl
	118	helo:
fe8f2338 MW	119	## Check that the caller's claimed identity is actually plausible.
	120	## This seems like it's a fairly effective filter on spamminess, but
	121	## it's too blunt a tool. Rather than reject, add a warning header.
	122	## Only we can't do this the easy way, so save it up for use in MAIL.
	123	## Also, we're liable to get a subsequent HELO (e.g., after STARTTLS)
	124	## and we should only care about the most recent one.
	125	warn set acl_c_helo_warning = false
	126	!condition = \
4ff4ad42 MW	127	${if and {{match_ip {$sender_host_address} \
	128	{<; 127.0.0.0/8 ; ::1}} \
	129	{match_domain {$sender_helo_name} \
	130	{localhost : +thishost}}}}
	131	!condition = \
fe8f2338 MW	132	${if exists {CONF_sysconf_dir/helo.conf} \
	133	{${lookup {$sender_helo_name} \
	134	partial0-lsearch \
	135	{CONF_sysconf_dir/helo.conf} \
	136	{${if match_ip \
	137	{$sender_host_address} \
4587a704	138	{<; $value}}}}}}
fe8f2338 MW	139	!verify = helo
fe8f2338 MW	140	set acl_c_helo_warning = true
185b5456 MW	141
	142	accept
	143
	144	SECTION(global, acl)m4_dnl
284c9d7e MW	145	acl_not_smtp_start = not_smtp_start
	146	SECTION(acl, misc)m4_dnl
	147	not_smtp_start:
	148	## Record the user's name.
	149	warn set acl_c_user = $sender_ident
	150
	151	## Done.
	152	accept
	153
	154	SECTION(global, acl)m4_dnl
185b5456 MW	155	acl_smtp_mail = mail
	156	SECTION(acl, mail)m4_dnl
	157	mail:
	158
fe8f2338	159	## If we stashed a warning header about HELO from earlier, we should
2f0841ce MW	160	## add it now. Only don't bother if the client has authenticated
	161	## successfully for submission (because we can't expect mobile
	162	## clients to be properly set up knowing their names), or it's one of
	163	## our own satellites (because they're either properly set up anyway,
	164	## or satellites using us as a smarthost).
fe8f2338	165	warn condition = $acl_c_helo_warning
2f0841ce MW	166	!condition = ${if eq{$acl_c_mode}{submission}}
2f0841ce MW	167	!hosts = +allnets
61295d9c MW	168	WARNING_HEADER(BADHELO,
	169	<:Client's HELO doesn't match its IP address.\n\t\
	170	helo-name=$sender_helo_name \
	171	address=$sender_host_address:>)
fe8f2338	172
185b5456 MW	173	## Always allow the empty sender, so that we can receive bounces.
	174	accept senders = :
	175
5051a30f MW	176	## Ensure that the sender looks valid.
5051a30f MW	177	require acl = mail_check_sender
185b5456 MW	178
	179	## If this is directly from a client then hack on it for a while.
	180	warn condition = ${if eq{$acl_c_mode}{submission}}
12d3b444	181	control = submission/sender_retain
185b5456	182
284c9d7e MW	183	## Insist that a local client connect through TLS.
	184	deny message = Hosts within CONF_master_domain must use TLS
	185	!condition = ${if eq{$acl_c_mode}{submission}}
	186	hosts = +allnets
	187	!encrypted = *
	188
	189	## Check that a submitted message's sender address is allowable.
	190	require acl = mail_check_auth
	191
185b5456 MW	192	SECTION(acl, mail-tail)m4_dnl
	193	## And we're done.
	194	accept
	195
5051a30f MW	196	SECTION(acl, misc)m4_dnl
	197	mail_check_sender:
	198
	199	## See whether there's a special exception for this sender domain.
	200	accept senders = ${LOOKUP_DOMAIN($sender_address_domain,
	201	{KV(senders, {$value}{})},
	202	{})}
	203
	204	## Ensure that the sender is routable. This is important to prevent
	205	## undeliverable bounces.
	206	require message = Invalid sender; \
	207	($sender_verify_failure; $acl_verify_message)
	208	verify = sender
	209
	210	## We're good, then.
	211	accept
	212
185b5456 MW	213	SECTION(global, acl)m4_dnl
	214	acl_smtp_connect = connect
	215	SECTION(acl, connect)m4_dnl
	216	connect:
	217	SECTION(acl, connect-tail)m4_dnl
e12c9586	218	## Configure variables according to the submission mode.
185b5456	219	warn acl = check_submission
e12c9586 MW	220
e12c9586 MW	221	## Done.
185b5456 MW	222	accept
	223
	224	check_submission:
	225	## See whether this message needs hacking on.
4ff4ad42	226	accept !hosts = +thishost
185b5456 MW	227	!condition = ${if ={$received_port}{CONF_submission_port}}
	228	set acl_c_mode = relay
	229
	230	## Remember to apply submission controls.
	231	warn set acl_c_mode = submission
	232
	233	## Done.
	234	accept
	235
	236	SECTION(global, acl)m4_dnl
	237	acl_smtp_rcpt = rcpt
	238	SECTION(acl, rcpt)m4_dnl
	239	rcpt:
	240
	241	## Reject if the client isn't allowed to relay and the recipient
	242	## isn't in one of our known domains.
e4666f2d MW	243	require message = Relaying not permitted
e4666f2d MW	244	acl = check_relay
185b5456 MW	245
	246	## Ensure that the recipient is routable.
	247	require message = Invalid recipient \
	248	($recipient_verify_failure; $acl_verify_message)
	249	verify = recipient
	250
e4666f2d MW	251	SECTION(acl, misc)m4_dnl
	252	check_relay:
	253	## Accept either if the client is allowed to relay through us, or if
	254	## we're the correct place to send this mail.
	255
	256	## Known clients and authenticated users are OK.
	257	accept hosts = CONF_relay_clients
	258	accept authenticated = *
	259
	260	## Known domains are OK.
	261	accept domains = +public
	262
	263	## Finally, domains in our table are OK, unless they say they aren't.
	264	accept domains = \
	265	${if exists{CONF_sysconf_dir/domains.conf} \
	266	{partial0-lsearch; CONF_sysconf_dir/domains.conf}}
	267	condition = DOMKV(service, {$value}{true})
	268
	269	## Nope, that's not allowed.
	270	deny
	271
185b5456 MW	272	SECTION(acl, rcpt-tail)m4_dnl
	273	## Everything checks out OK: let this one go through.
	274	accept
	275
	276	SECTION(global, acl)m4_dnl
	277	acl_smtp_data = data
	278	SECTION(acl, data)m4_dnl
	279	data:
	280
	281	SECTION(acl, data-tail)m4_dnl
	282	accept
	283
	284	SECTION(global, acl)m4_dnl
	285	acl_smtp_expn = expn_vrfy
	286	acl_smtp_vrfy = expn_vrfy
e4fe8925	287	SECTION(acl, misc)m4_dnl
185b5456 MW	288	expn_vrfy:
	289	accept hosts = +trusted
	290	deny message = Suck it and see
	291
	292	DIVERT(null)
	293	###--------------------------------------------------------------------------
284c9d7e MW	294	### Verification of sender address.
	295
	296	SECTION(acl, misc)m4_dnl
	297	mail_check_auth:
	298
	299	## If this isn't a submission then it doesn't need checking.
	300	accept condition = ${if !eq{$acl_c_mode}{submission}}
	301
	302	## If the caller hasn't formally authenticated, but this is a
	303	## loopback connection, then we can trust identd to tell us the right
	304	## answer. So we should stash the right name somewhere consistent.
	305	warn set acl_c_user = $authenticated_id
4ff4ad42	306	hosts = +thishost
284c9d7e	307	!authenticated = *
ff4c943d	308	condition = ${if def:sender_ident}
284c9d7e MW	309	set acl_c_user = $sender_ident
284c9d7e MW	310
ff4c943d	311	## User must be authenticated by now.
284c9d7e	312	deny message = Sender not authenticated
ff4c943d	313	condition = ${if !def:acl_c_user}
284c9d7e	314
284c9d7e MW	315	## All done.
	316	accept
	317
	318	DIVERT(null)
	319	###--------------------------------------------------------------------------
185b5456 MW	320	### Common options for forwarding routers.
	321
	322	## We're pretty permissive here.
	323	m4_define(<:FILTER_BASE:>,
	324	<:driver = redirect
	325	modemask = 002
	326	check_owner = false
	327	check_group = false
	328	allow_filter = true
	329	allow_defer = true
	330	allow_fail = true
	331	forbid_blackhole = false
	332	check_ancestor = true:>)
	333
	334	## Common options for forwarding routers at verification time.
	335	m4_define(<:FILTER_VERIFY:>,
	336	<:verify_only = true
	337	user = CONF_filter_user
	338	forbid_filter_dlfunc = true
	339	forbid_filter_logwrite = true
	340	forbid_filter_perl = true
	341	forbid_filter_readsocket = true
	342	forbid_filter_run = true
	343	file_transport = dummy
	344	directory_transport = dummy
	345	pipe_transport = dummy
	346	reply_transport = dummy:>)
	347
	348	## Transports for redirection filters.
	349	m4_define(<:FILTER_TRANSPORTS:>,
7ab75d6f	350	<:file_transport = mailbox
185b5456 MW	351	directory_transport = maildir
	352	pipe_transport = pipe
	353	reply_transport = reply:>)
	354
7ab75d6f MW	355	m4_define(<:FILTER_ROUTER:>,
	356	<:$1_vrf:
	357	$2
	358	FILTER_VERIFY<::>$3
	359	$1:
	360	$2
	361	verify = no
	362	FILTER_TRANSPORTS<::>$4:>)
	363
185b5456 MW	364	DIVERT(null)
185b5456 MW	365	###--------------------------------------------------------------------------
3e031e77 MW	366	### Common routers.
	367
	368	SECTION(routers, alias)m4_dnl
	369	## Look up the local part in the address map.
	370	alias:
	371	driver = redirect
	372	allow_fail = true
	373	allow_defer = true
	374	user = CONF_filter_user
	375	FILTER_TRANSPORTS
	376	local_parts = nwildlsearch; CONF_alias_file
	377	data = ${expand:$local_part_data}
	378	SECTION(routers, alias-opts)m4_dnl
	379
	380	DIVERT(null)
	381	###--------------------------------------------------------------------------
185b5456 MW	382	### Some standard transports.
	383
	384	m4_define(<:USER_DELIVERY:>,
	385	<:delivery_date_add = true
	386	envelope_to_add = true
	387	return_path_add = true:>)
	388
1e5ccd7c MW	389	m4_define(<:APPLY_HEADER_CHANGES:>,
	390	<:headers_add = m4_ifelse(<:$1:>, <::>,
	391	<:$acl_m_hdradd:>,
	392	<:${if def:acl_m_hdradd{$acl_m_hdradd\n}}\
	393	$1:>)
	394	headers_remove = m4_ifelse(<:$2:>, <::>,
	395	<:$acl_m_hdrrm:>,
	396	<:${if def:acl_m_hdrrm{$acl_m_hdrrm:}}\
	397	$2:>):>)
	398
185b5456	399	SECTION(transports)m4_dnl
fa5a92c6 MW	400	## A standard transport for remote delivery. By default, try to do TLS, and
	401	## don't worry too much if it's not very secure: the alternative is sending
	402	## in plaintext anyway. But all of this can be overridden from the
beb15dae MW	403	## `domains.conf' file. Annoyingly, the `tls_dh_min_bits' setting isn't
	404	## expanded before use, so we can't set it the obvious way. Instead, encode
	405	## it into the transport name. This is very unpleasant, of course.
534d411b MW	406	smtp:
534d411b MW	407	driver = smtp
1e5ccd7c	408	APPLY_HEADER_CHANGES
534d411b MW	409	tls_require_ciphers = CONF_acceptable_ciphers
	410	tls_dh_min_bits = 1020
	411	tls_tempfail_tryclear = true
	412
beb15dae MW	413	m4_define(<:SMTP_TRANS_DHBITS:>,
beb15dae MW	414	<:driver = smtp
1e5ccd7c	415	APPLY_HEADER_CHANGES
ae9744ce	416	hosts_try_auth = *
fa5a92c6	417	hosts_require_tls = DOMKV(tls-peer-ca, {*}{})
ae9744ce MW	418	hosts_require_auth = \
ae9744ce MW	419	${if bool {DOMKV(require-auth, {$value}{false})} {*}{}}
fa5a92c6 MW	420	tls_certificate = DOMKV(tls-certificate, {${expand:$value}}fail)
	421	tls_privatekey = DOMKV(tls-private-key, {${expand:$value}}fail)
	422	tls_verify_certificates = DOMKV(tls-peer-ca, {${expand:$value}}fail)
	423	tls_require_ciphers = \
	424	DOMKV(tls-ciphers,
	425	{${extract {${expand:$value}} \
	426	{ good = CONF_good_ciphers \
	427	any = CONF_acceptable_ciphers } \
	428	{$value} \
	429	{${expand:$value}}}} \
	430	{CONF_acceptable_ciphers})
beb15dae MW	431	tls_dh_min_bits = $1
beb15dae MW	432	tls_tempfail_tryclear = true:>)m4_dnl
beb15dae MW	433	smtp_dhbits_1024:
	434	SMTP_TRANS_DHBITS(1020)
	435	smtp_dhbits_2048:
	436	SMTP_TRANS_DHBITS(2046)
185b5456 MW	437
	438	## Transport to a local SMTP server; use TLS and perform client
	439	## authentication.
	440	smtp_local:
	441	driver = smtp
1e5ccd7c	442	APPLY_HEADER_CHANGES
185b5456	443	hosts_require_tls = *
163774f0	444	tls_certificate = CONF_sysconf_dir/client.certlist
185b5456 MW	445	tls_privatekey = CONF_sysconf_dir/client.key
	446	tls_verify_certificates = CONF_ca_dir/ca.cert
	447	tls_require_ciphers = CONF_good_ciphers
b6d74252	448	tls_dh_min_bits = 2046
185b5456 MW	449	tls_tempfail_tryclear = false
185b5456 MW	450	authenticated_sender = ${if def:authenticated_id \
0bed9b7f	451	{$authenticated_id@CONF_master_domain} \
185b5456 MW	452	fail}
	453
	454	## A standard transport for local delivery.
	455	deliver:
	456	driver = appendfile
1e5ccd7c	457	APPLY_HEADER_CHANGES
185b5456	458	file = /var/mail/$local_part
8f6af4ae MW	459	group = mail
	460	mode = 0600
	461	mode_fail_narrower = false
185b5456 MW	462	USER_DELIVERY
	463
	464	## Transports for user filters.
	465	mailbox:
	466	driver = appendfile
1e5ccd7c	467	APPLY_HEADER_CHANGES
8f6af4ae	468	initgroups = true
185b5456 MW	469	USER_DELIVERY
	470
	471	maildir:
	472	driver = appendfile
1e5ccd7c	473	APPLY_HEADER_CHANGES
185b5456	474	maildir_format = true
8f6af4ae	475	initgroups = true
185b5456 MW	476	USER_DELIVERY
	477
	478	pipe:
	479	driver = pipe
1e5ccd7c	480	APPLY_HEADER_CHANGES
8f6af4ae MW	481	path = ${if and {{def:home} {exists{$home/bin}}} {$home/bin:} {}}\
	482	/usr/local/bin:/usr/local/sbin:\
	483	/usr/bin:/usr/sbin:/bin:/sbin
	484	initgroups = true
	485	umask = 002
	486	return_fail_output = true
	487	log_output = true
185b5456 MW	488
	489	## A special dummy transport for use during address verification.
	490	dummy:
	491	driver = appendfile
	492	file = /dev/null
	493
	494	DIVERT(null)
	495	###--------------------------------------------------------------------------
	496	### Retry configuration.
	497
	498	SECTION(retry, default)m4_dnl
	499	## Default.
	500	* * \
	501	F,2h,15m; G,16h,2h,1.5; F,4d,6h
	502
	503	DIVERT(null)
	504	###----- That's all, folks --------------------------------------------------