[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_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:
	## Don't worry if this is local submission.  MUAs won't necessarily
	## have a clear idea of their hostnames.  (For some reason.)
	accept	 condition = ${if !eq{$acl_c_mode}{submission}}

	## 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
		 control = no_enforce_sync

	## 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
## Be persistent when sending to the site relay.  It ought to work, but
## particularly satellites such as laptops often encounter annoying temporary
## failures due to network unavailability, and the usual gradual policy can
## leave mail building up for no good reason.
CONF_smarthost				* \
	F,4d,15m

## 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
1dda4df9	108	tls_certificate = CONF_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:
a891f462 MW	128	## Don't worry if this is local submission. MUAs won't necessarily
	129	## have a clear idea of their hostnames. (For some reason.)
	130	accept condition = ${if !eq{$acl_c_mode}{submission}}
	131
fe8f2338 MW	132	## Check that the caller's claimed identity is actually plausible.
	133	## This seems like it's a fairly effective filter on spamminess, but
	134	## it's too blunt a tool. Rather than reject, add a warning header.
	135	## Only we can't do this the easy way, so save it up for use in MAIL.
	136	## Also, we're liable to get a subsequent HELO (e.g., after STARTTLS)
	137	## and we should only care about the most recent one.
	138	warn set acl_c_helo_warning = false
4ff4ad42 MW	139	!condition = \
	140	${if and {{match_ip {$sender_host_address} \
	141	{<; 127.0.0.0/8 ; ::1}} \
	142	{match_domain {$sender_helo_name} \
	143	{localhost : +thishost}}}}
fe8f2338 MW	144	!condition = \
	145	${if exists {CONF_sysconf_dir/helo.conf} \
	146	{${lookup {$sender_helo_name} \
	147	partial0-lsearch \
	148	{CONF_sysconf_dir/helo.conf} \
	149	{${if match_ip \
	150	{$sender_host_address} \
4587a704	151	{<; $value}}}}}}
fe8f2338 MW	152	!verify = helo
fe8f2338 MW	153	set acl_c_helo_warning = true
185b5456 MW	154
	155	accept
	156
284c9d7e MW	157	SECTION(global, acl)m4_dnl
	158	acl_not_smtp_start = not_smtp_start
	159	SECTION(acl, misc)m4_dnl
	160	not_smtp_start:
	161	## Record the user's name.
	162	warn set acl_c_user = $sender_ident
e9015968	163	set acl_m_user = $sender_ident
284c9d7e MW	164
	165	## Done.
	166	accept
	167
185b5456 MW	168	SECTION(global, acl)m4_dnl
	169	acl_smtp_mail = mail
	170	SECTION(acl, mail)m4_dnl
	171	mail:
	172
fe8f2338	173	## If we stashed a warning header about HELO from earlier, we should
2f0841ce MW	174	## add it now. Only don't bother if the client has authenticated
	175	## successfully for submission (because we can't expect mobile
	176	## clients to be properly set up knowing their names), or it's one of
	177	## our own satellites (because they're either properly set up anyway,
	178	## or satellites using us as a smarthost).
fe8f2338	179	warn condition = $acl_c_helo_warning
2f0841ce MW	180	!condition = ${if eq{$acl_c_mode}{submission}}
2f0841ce MW	181	!hosts = +allnets
61295d9c MW	182	WARNING_HEADER(BADHELO,
	183	<:Client's HELO doesn't match its IP address.\n\t\
	184	helo-name=$sender_helo_name \
	185	address=$sender_host_address:>)
fe8f2338	186
185b5456 MW	187	## Always allow the empty sender, so that we can receive bounces.
	188	accept senders = :
	189
5051a30f MW	190	## Ensure that the sender looks valid.
5051a30f MW	191	require acl = mail_check_sender
185b5456 MW	192
	193	## If this is directly from a client then hack on it for a while.
	194	warn condition = ${if eq{$acl_c_mode}{submission}}
12d3b444	195	control = submission/sender_retain
185b5456	196
284c9d7e MW	197	## Insist that a local client connect through TLS.
	198	deny message = Hosts within CONF_master_domain must use TLS
	199	!condition = ${if eq{$acl_c_mode}{submission}}
	200	hosts = +allnets
	201	!encrypted = *
	202
	203	## Check that a submitted message's sender address is allowable.
	204	require acl = mail_check_auth
	205
185b5456 MW	206	SECTION(acl, mail-tail)m4_dnl
	207	## And we're done.
	208	accept
	209
5051a30f MW	210	SECTION(acl, misc)m4_dnl
	211	mail_check_sender:
	212
	213	## See whether there's a special exception for this sender domain.
	214	accept senders = ${LOOKUP_DOMAIN($sender_address_domain,
	215	{KV(senders, {$value}{})},
	216	{})}
	217
	218	## Ensure that the sender is routable. This is important to prevent
	219	## undeliverable bounces.
	220	require message = Invalid sender; \
	221	($sender_verify_failure; $acl_verify_message)
	222	verify = sender
	223
	224	## We're good, then.
	225	accept
	226
185b5456 MW	227	SECTION(global, acl)m4_dnl
	228	acl_smtp_connect = connect
	229	SECTION(acl, connect)m4_dnl
	230	connect:
	231	SECTION(acl, connect-tail)m4_dnl
e12c9586	232	## Configure variables according to the submission mode.
185b5456	233	warn acl = check_submission
e12c9586 MW	234
e12c9586 MW	235	## Done.
185b5456 MW	236	accept
	237
	238	check_submission:
	239	## See whether this message needs hacking on.
4ff4ad42	240	accept !hosts = +thishost
185b5456 MW	241	!condition = ${if ={$received_port}{CONF_submission_port}}
	242	set acl_c_mode = relay
	243
	244	## Remember to apply submission controls.
	245	warn set acl_c_mode = submission
54341a70	246	control = no_enforce_sync
185b5456 MW	247
	248	## Done.
	249	accept
	250
	251	SECTION(global, acl)m4_dnl
	252	acl_smtp_rcpt = rcpt
	253	SECTION(acl, rcpt)m4_dnl
	254	rcpt:
	255
	256	## Reject if the client isn't allowed to relay and the recipient
	257	## isn't in one of our known domains.
e4666f2d MW	258	require message = Relaying not permitted
e4666f2d MW	259	acl = check_relay
185b5456 MW	260
	261	## Ensure that the recipient is routable.
	262	require message = Invalid recipient \
	263	($recipient_verify_failure; $acl_verify_message)
	264	verify = recipient
	265
e4666f2d MW	266	SECTION(acl, misc)m4_dnl
	267	check_relay:
	268	## Accept either if the client is allowed to relay through us, or if
	269	## we're the correct place to send this mail.
	270
	271	## Known clients and authenticated users are OK.
a0375fd9 MW	272	accept hosts = CONF_relay_clients
a0375fd9 MW	273	accept authenticated = *
e4666f2d MW	274
e4666f2d MW	275	## Known domains are OK.
a0375fd9	276	accept domains = +public
e4666f2d MW	277
e4666f2d MW	278	## Finally, domains in our table are OK, unless they say they aren't.
a0375fd9 MW	279	accept domains = \
a0375fd9 MW	280	${if exists{CONF_sysconf_dir/domains.conf} \
e4666f2d	281	{partial0-lsearch; CONF_sysconf_dir/domains.conf}}
a0375fd9	282	condition = DOMKV(service, {$value}{true})
e4666f2d MW	283
	284	## Nope, that's not allowed.
	285	deny
	286
185b5456 MW	287	SECTION(acl, rcpt-tail)m4_dnl
	288	## Everything checks out OK: let this one go through.
	289	accept
	290
	291	SECTION(global, acl)m4_dnl
	292	acl_smtp_data = data
	293	SECTION(acl, data)m4_dnl
	294	data:
5d2f8b65 MW	295	## Don't accept messages with overly-long lines.
	296	deny message = line length exceeds SMTP permitted maximum: \
	297	$max_received_linelength > 998
	298	condition = ${if >{$max_received_linelength}{998}}
185b5456 MW	299
	300	SECTION(acl, data-tail)m4_dnl
	301	accept
	302
	303	SECTION(global, acl)m4_dnl
	304	acl_smtp_expn = expn_vrfy
	305	acl_smtp_vrfy = expn_vrfy
e4fe8925	306	SECTION(acl, misc)m4_dnl
185b5456 MW	307	expn_vrfy:
	308	accept hosts = +trusted
	309	deny message = Suck it and see
	310
	311	DIVERT(null)
	312	###--------------------------------------------------------------------------
284c9d7e MW	313	### Verification of sender address.
	314
	315	SECTION(acl, misc)m4_dnl
	316	mail_check_auth:
	317
	318	## If this isn't a submission then it doesn't need checking.
	319	accept condition = ${if !eq{$acl_c_mode}{submission}}
	320
	321	## If the caller hasn't formally authenticated, but this is a
	322	## loopback connection, then we can trust identd to tell us the right
	323	## answer. So we should stash the right name somewhere consistent.
	324	warn set acl_c_user = $authenticated_id
4ff4ad42	325	hosts = +thishost
284c9d7e	326	!authenticated = *
ff4c943d	327	condition = ${if def:sender_ident}
284c9d7e MW	328	set acl_c_user = $sender_ident
284c9d7e MW	329
ff4c943d	330	## User must be authenticated by now.
284c9d7e	331	deny message = Sender not authenticated
ff4c943d	332	condition = ${if !def:acl_c_user}
284c9d7e	333
e9015968 MW	334	## Set the per-message authentication flag, since we now know that
	335	## there's a sensible value.
	336	warn set acl_m_user = $acl_c_user
	337
284c9d7e MW	338	## All done.
	339	accept
	340
	341	DIVERT(null)
	342	###--------------------------------------------------------------------------
185b5456 MW	343	### Common options for forwarding routers.
	344
	345	## We're pretty permissive here.
	346	m4_define(<:FILTER_BASE:>,
	347	<:driver = redirect
	348	modemask = 002
	349	check_owner = false
	350	check_group = false
	351	allow_filter = true
	352	allow_defer = true
	353	allow_fail = true
	354	forbid_blackhole = false
	355	check_ancestor = true:>)
	356
	357	## Common options for forwarding routers at verification time.
	358	m4_define(<:FILTER_VERIFY:>,
	359	<:verify_only = true
	360	user = CONF_filter_user
	361	forbid_filter_dlfunc = true
	362	forbid_filter_logwrite = true
	363	forbid_filter_perl = true
	364	forbid_filter_readsocket = true
	365	forbid_filter_run = true
	366	file_transport = dummy
	367	directory_transport = dummy
	368	pipe_transport = dummy
	369	reply_transport = dummy:>)
	370
	371	## Transports for redirection filters.
	372	m4_define(<:FILTER_TRANSPORTS:>,
7ab75d6f	373	<:file_transport = mailbox
185b5456 MW	374	directory_transport = maildir
	375	pipe_transport = pipe
	376	reply_transport = reply:>)
	377
7ab75d6f MW	378	m4_define(<:FILTER_ROUTER:>,
	379	<:$1_vrf:
	380	$2
	381	FILTER_VERIFY<::>$3
	382	$1:
	383	$2
	384	verify = no
	385	FILTER_TRANSPORTS<::>$4:>)
	386
185b5456 MW	387	DIVERT(null)
185b5456 MW	388	###--------------------------------------------------------------------------
3e031e77 MW	389	### Common routers.
	390
	391	SECTION(routers, alias)m4_dnl
	392	## Look up the local part in the address map.
	393	alias:
	394	driver = redirect
	395	allow_fail = true
	396	allow_defer = true
	397	user = CONF_filter_user
	398	FILTER_TRANSPORTS
	399	local_parts = nwildlsearch; CONF_alias_file
	400	data = ${expand:$local_part_data}
	401	SECTION(routers, alias-opts)m4_dnl
	402
	403	DIVERT(null)
	404	###--------------------------------------------------------------------------
185b5456 MW	405	### Some standard transports.
	406
	407	m4_define(<:USER_DELIVERY:>,
	408	<:delivery_date_add = true
	409	envelope_to_add = true
	410	return_path_add = true:>)
	411
1e5ccd7c MW	412	m4_define(<:APPLY_HEADER_CHANGES:>,
	413	<:headers_add = m4_ifelse(<:$1:>, <::>,
	414	<:$acl_m_hdradd:>,
	415	<:${if def:acl_m_hdradd{$acl_m_hdradd\n}}\
	416	$1:>)
	417	headers_remove = m4_ifelse(<:$2:>, <::>,
	418	<:$acl_m_hdrrm:>,
	419	<:${if def:acl_m_hdrrm{$acl_m_hdrrm:}}\
	420	$2:>):>)
	421
5d2f8b65 MW	422	m4_define(<:SMTP_DELIVERY:>,
	423	<:## Prevent sending messages with overly long lines. The use of
	424	## `message_size_limit' here is somewhat misleading.
	425	message_size_limit = ${if >{$max_received_linelength}{998}{1}{0}}:>)
	426
185b5456	427	SECTION(transports)m4_dnl
fa5a92c6 MW	428	## A standard transport for remote delivery. By default, try to do TLS, and
	429	## don't worry too much if it's not very secure: the alternative is sending
	430	## in plaintext anyway. But all of this can be overridden from the
beb15dae MW	431	## `domains.conf' file. Annoyingly, the `tls_dh_min_bits' setting isn't
	432	## expanded before use, so we can't set it the obvious way. Instead, encode
	433	## it into the transport name. This is very unpleasant, of course.
534d411b MW	434	smtp:
534d411b MW	435	driver = smtp
1e5ccd7c	436	APPLY_HEADER_CHANGES
534d411b	437	tls_require_ciphers = CONF_acceptable_ciphers
7b50997d	438	tls_dh_min_bits = 508
534d411b MW	439	tls_tempfail_tryclear = true
534d411b MW	440
beb15dae MW	441	m4_define(<:SMTP_TRANS_DHBITS:>,
beb15dae MW	442	<:driver = smtp
5d2f8b65	443	SMTP_DELIVERY
1e5ccd7c	444	APPLY_HEADER_CHANGES
ae9744ce	445	hosts_try_auth = *
fa5a92c6	446	hosts_require_tls = DOMKV(tls-peer-ca, {*}{})
ae9744ce MW	447	hosts_require_auth = \
ae9744ce MW	448	${if bool {DOMKV(require-auth, {$value}{false})} {*}{}}
fa5a92c6 MW	449	tls_certificate = DOMKV(tls-certificate, {${expand:$value}}fail)
	450	tls_privatekey = DOMKV(tls-private-key, {${expand:$value}}fail)
	451	tls_verify_certificates = DOMKV(tls-peer-ca, {${expand:$value}}fail)
	452	tls_require_ciphers = \
	453	DOMKV(tls-ciphers,
	454	{${extract {${expand:$value}} \
	455	{ good = CONF_good_ciphers \
	456	any = CONF_acceptable_ciphers } \
	457	{$value} \
	458	{${expand:$value}}}} \
	459	{CONF_acceptable_ciphers})
beb15dae MW	460	tls_dh_min_bits = $1
beb15dae MW	461	tls_tempfail_tryclear = true:>)m4_dnl
7b50997d MW	462	smtp_dhbits_512:
	463	SMTP_TRANS_DHBITS(508)
	464	smtp_dhbits_768:
	465	SMTP_TRANS_DHBITS(764)
beb15dae MW	466	smtp_dhbits_1024:
	467	SMTP_TRANS_DHBITS(1020)
	468	smtp_dhbits_2048:
7b50997d	469	SMTP_TRANS_DHBITS(2044)
185b5456 MW	470
	471	## Transport to a local SMTP server; use TLS and perform client
	472	## authentication.
	473	smtp_local:
	474	driver = smtp
5d2f8b65	475	SMTP_DELIVERY
1e5ccd7c	476	APPLY_HEADER_CHANGES
185b5456	477	hosts_require_tls = *
163774f0	478	tls_certificate = CONF_sysconf_dir/client.certlist
185b5456 MW	479	tls_privatekey = CONF_sysconf_dir/client.key
	480	tls_verify_certificates = CONF_ca_dir/ca.cert
	481	tls_require_ciphers = CONF_good_ciphers
b6d74252	482	tls_dh_min_bits = 2046
185b5456	483	tls_tempfail_tryclear = false
10c331d7 MW	484	authenticated_sender_force = true
	485	authenticated_sender = \
	486	${if def:acl_m_user {$acl_m_user@CONF_master_domain} \
	487	{${if def:authenticated_sender {$authenticated_sender} \
	488	fail}}}
185b5456 MW	489
	490	## A standard transport for local delivery.
	491	deliver:
	492	driver = appendfile
1e5ccd7c	493	APPLY_HEADER_CHANGES
185b5456	494	file = /var/mail/$local_part
8f6af4ae MW	495	group = mail
	496	mode = 0600
	497	mode_fail_narrower = false
185b5456 MW	498	USER_DELIVERY
	499
	500	## Transports for user filters.
	501	mailbox:
	502	driver = appendfile
1e5ccd7c	503	APPLY_HEADER_CHANGES
8f6af4ae	504	initgroups = true
185b5456 MW	505	USER_DELIVERY
	506
	507	maildir:
	508	driver = appendfile
1e5ccd7c	509	APPLY_HEADER_CHANGES
185b5456	510	maildir_format = true
8f6af4ae	511	initgroups = true
185b5456 MW	512	USER_DELIVERY
	513
	514	pipe:
	515	driver = pipe
1e5ccd7c	516	APPLY_HEADER_CHANGES
8f6af4ae MW	517	path = ${if and {{def:home} {exists{$home/bin}}} {$home/bin:} {}}\
	518	/usr/local/bin:/usr/local/sbin:\
	519	/usr/bin:/usr/sbin:/bin:/sbin
	520	initgroups = true
	521	umask = 002
	522	return_fail_output = true
	523	log_output = true
185b5456 MW	524
	525	## A special dummy transport for use during address verification.
	526	dummy:
	527	driver = appendfile
	528	file = /dev/null
	529
	530	DIVERT(null)
	531	###--------------------------------------------------------------------------
	532	### Retry configuration.
	533
	534	SECTION(retry, default)m4_dnl
af4b4ca8 MW	535	## Be persistent when sending to the site relay. It ought to work, but
	536	## particularly satellites such as laptops often encounter annoying temporary
	537	## failures due to network unavailability, and the usual gradual policy can
	538	## leave mail building up for no good reason.
	539	CONF_smarthost * \
	540	F,4d,15m
	541
185b5456 MW	542	## Default.
	543	* * \
	544	F,2h,15m; G,16h,2h,1.5; F,4d,6h
	545
	546	DIVERT(null)
	547	###----- That's all, folks --------------------------------------------------