satellite.m4: Apply `/etc/aliases' to master-domain-qualified addresses.

[exim-config] / base.m4

diff --git a/base.m4 b/base.m4
index c0dd892..0aadb78 100644 (file)
--- a/base.m4
+++ b/base.m4
@@ -44,6 +44,7 @@ extra_local_interfaces = <; 0.0.0.0 ; ::0
 
 SECTION(global, resource)m4_dnl
 deliver_queue_load_max = 8
+message_size_limit = 500M
 queue_only_load = 12
 smtp_accept_max = 16
 smtp_accept_queue = 32
@@ -125,6 +126,10 @@ 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.
@@ -208,8 +213,7 @@ mail_check_sender:
 
        ## See whether there's a special exception for this sender domain.
        accept   senders = ${LOOKUP_DOMAIN($sender_address_domain,
-                            {KV(senders, {$value}{})},
-                            {})}
+                            {KV(senders)})}
 
        ## Ensure that the sender is routable.  This is important to prevent
        ## undeliverable bounces.
@@ -239,6 +243,7 @@ check_submission:
 
        ## Remember to apply submission controls.
        warn     set acl_c_mode = submission
+                control = no_enforce_sync
 
        ## Done.
        accept
@@ -414,6 +419,64 @@ m4_define(<:APPLY_HEADER_CHANGES:>,
                <:${if def:acl_m_hdrrm{$acl_m_hdrrm:}}\
                $2:>):>)
 
+m4_define(<:DKIM_SIGN_P:>,
+       <:and {{exists{CONF_sysconf_dir/dkim-sign.conf}} \
+              {!def:h_DKIM-Signature:} \
+              {!def:h_List-ID:} \
+              {or {{def:authenticated_id} \
+                   {def:authenticated_sender}}}}:>)
+
+m4_define(<:DKIM_KEYS_INSTANCE:>,
+       <:${lookup {${domain:$h_From:}} partial0-lsearch \
+                       {CONF_sysconf_dir/dkim-sign.conf} \
+               _LOOKUP_ARGS(<:$1:>, <:$2:>)}:>)
+m4_define(<:DKIM_KEYS_STATE:>, <:${lookup {$1} lsearch \
+               {DKIM_KEYS_INSTANCE(<:{CONF_dkim_keys_dir/$value/active/dkim-keys.state}:>)} \
+       _LOOKUP_ARGS(<:$2:>, <:$3:>, <:fail:>)}:>)
+m4_define(<:DKIM_KEYS_INFO:>, <:DKIM_KEYS_STATE(<:params:>,
+       <:{${if and {{>={$tod_epoch}{KV(t0)}} \
+                   {<{$tod_epoch}{${eval:KV(t0) + KV(n)*KV(step)}}}} \
+               {DKIM_KEYS_STATE(<:info.${eval:($tod_epoch - KV(t0))/KV(step)}:>,
+                       <:$1:>, <:$2:>)} \
+               m4_ifelse(<:$2:>, <::>, <:fail:>, <:$2:>)}}:>,
+       m4_ifelse(<:$2:>, <::>, <:fail:>, <:$2:>)):>)
+
+m4_define(<:DKIM_SIGN:>,
+       <:dkim_domain = \
+               ${if DKIM_SIGN_P \
+                       {DKIM_KEYS_INSTANCE({${domain:$h_From:}})}}
+       dkim_selector = DKIM_KEYS_INFO(<:{KV(k)}:>)
+       dkim_private_key = \
+               DKIM_KEYS_INSTANCE(<:m4_dnl
+                       {CONF_dkim_keys_dir/$value/active/$dkim_selector.priv}:>)
+       dkim_canon = relaxed
+       dkim_strict = true
+       ## The following ridiculous stunt does two important jobs.  Firstly,
+       ## and more obviously, it arranges to include one more copy of each
+       ## header name than the message actually contains, thereby causing
+       ## the signature to fail if another header with the same name is
+       ## added.  And secondly, and far more subtly, it also trims the
+       ## spaces from the header names so that they're in the format that
+       ## the signing machinery secretly wants.
+       dkim_sign_headers = \
+               ${sg {${map {CONF_dkim_headers : \
+                            X-CONF_header_token-DKIM-Key-Publication} \
+                           {$item${sg {${expand:\$h_$item:}\n} \
+                                      {((?:[^\n]+|\n\\s+)*)\n} \
+                                      {:$item}}}}} \
+                    {::}{:}}
+       headers_add = \
+               ${if DKIM_SIGN_P \
+                       {DKIM_KEYS_INFO(<:m4_dnl
+                               {X-CONF_header_token-DKIM-Key-Publication: \
+                                       DKIM signature not suitable \
+                                       as evidence after delivery;\n\t\
+                                       DKIM private key KV(k) will be \
+                                       published\n\t\
+                                       at KV(u)\n\t\
+                                       on or before KV(tpub)}:>)}}:>)
+
+
 m4_define(<:SMTP_DELIVERY:>,
        <:## Prevent sending messages with overly long lines.  The use of
        ## `message_size_limit' here is somewhat misleading.
@@ -428,7 +491,9 @@ SECTION(transports)m4_dnl
 ## it into the transport name.  This is very unpleasant, of course.
 smtp:
        driver = smtp
+       SMTP_DELIVERY
        APPLY_HEADER_CHANGES
+       DKIM_SIGN
        tls_require_ciphers = CONF_acceptable_ciphers
        tls_dh_min_bits = 508
        tls_tempfail_tryclear = true
@@ -437,6 +502,7 @@ m4_define(<:SMTP_TRANS_DHBITS:>,
        <:driver = smtp
        SMTP_DELIVERY
        APPLY_HEADER_CHANGES
+       DKIM_SIGN
        hosts_try_auth = *
        hosts_require_tls = DOMKV(tls-peer-ca, {*}{})
        hosts_require_auth = \
@@ -527,6 +593,13 @@ 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