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

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:

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:>):>)

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