smtp transport: message_linelength_limit option. Bug 1684

[exim.git] / doc / doc-docbook / spec.xfpt

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index be3e7c925a23b8e5ee50dccb1a879d0afc4f53cd..5c6955e58abac61c3159b091dc49ab6436c13f27 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -4518,6 +4518,7 @@ appear in the correct order. Each flag is described in a separate item below.
 .cindex "queue" "routing"
 .cindex "routing" "whole queue before delivery"
 .cindex "first pass routing"
+.cindex "queue runner" "two phase"
 An option starting with &%-qq%& requests a two-stage queue run. In the first
 stage, the queue is scanned as if the &%queue_smtp_domains%& option matched
 every domain. Addresses are routed, local deliveries happen, but no remote
@@ -4525,6 +4526,10 @@ transports are run.
 
 .new
 Performance will be best if the &%queue_run_in_order%& option is false.
+If that is so and the &%queue_fast_ramp%& option is true then
+in the first phase of the run,
+once a threshold number of messages are routed for a given host,
+a delivery process is forked in parallel with the rest of the scan.
 .wen
 
 .cindex "hints database" "remembering routing"
@@ -6858,6 +6863,29 @@ The final resulting element can be a simple JSON type or a JSON object
 or array; for the latter two a string-representation of the JSON
 is returned.
 For elements of type string, the returned value is de-quoted.
+
+
+.new
+.next
+.cindex LMDB
+.cindex lookup lmdb
+.cindex database lmdb
+&(lmdb)&: The given file is an LMDB database.
+LMDB is a memory-mapped key-value store,
+with API modeled loosely on that of BerkeleyDB.
+See &url(https://symas.com/products/lightning-memory-mapped-database/)
+for the feature set and operation modes.
+
+Exim provides read-only access via the LMDB C library.
+The library can be obtained from &url(https://github.com/LMDB/lmdb)
+or your operating system package repository.
+To enable LMDB support in Exim set LOOKUP_LMDB=yes in &_Local/Makefile_&.
+
+You will need to separately create the LMDB database file,
+possibly using the &"mdb_load"& utility.
+.wen
+
+
 .next
 .cindex "linear search"
 .cindex "lookup" "lsearch"
@@ -14777,6 +14805,7 @@ See also the &'Policy controls'& section above.
 .row &%hold_domains%&                "hold delivery for these domains"
 .row &%local_interfaces%&            "for routing checks"
 .row &%queue_domains%&               "no immediate delivery for these"
+.row &%queue_fast_ramp%&             "parallel delivery with 2-phase queue run"
 .row &%queue_only%&                  "no immediate delivery at all"
 .row &%queue_only_file%&             "no immediate delivery if file exists"
 .row &%queue_only_load%&             "no immediate delivery if load is high"
@@ -16953,6 +16982,17 @@ domains that do not match are processed. All other deliveries wait until the
 next queue run. See also &%hold_domains%& and &%queue_smtp_domains%&.
 
 
+.new
+.option queue_fast_ramp main boolean false
+.cindex "queue runner" "two phase"
+.cindex "queue" "double scanning"
+If set to true, two-phase queue runs, initiated using &%-qq%& on the
+command line, may start parallel delivery processes during their first
+phase.  This will be done when a threshold number of messages have been
+routed for a single host.
+.wen
+
+
 .option queue_list_requires_admin main boolean true
 .cindex "restricting access to features"
 .oindex "&%-bp%&"
@@ -25432,6 +25472,20 @@ so can cause parallel connections to the same host if &%remote_max_parallel%&
 permits this.
 
 
+.new
+.option message_linelength_limit smtp integer 998
+.cindex "line length" limit
+This option sets the maximum line length, in bytes, that the transport
+will send.  Any messages with lines exceeding the given value
+will fail and a failure-DSN ("bounce") message will if possible be returned
+to the sender.
+The default value is that defined by the SMTP standards.
+
+It is generally wise to also check in the data ACL so that messages
+received via SMTP can be refused without producing a bounce.
+.wen
+
+
 .option multi_domain smtp boolean&!! true
 .vindex "&$domain$&"
 When this option is set, the &(smtp)& transport can handle a number of
@@ -29522,7 +29576,7 @@ tls_resumption_hosts = ${if inlist {$received_port}{587:465} {:}{*}}
 If the peer host matches the list after expansion then resumption
 is offered and/or accepted.
 
-The &%tls_resumption_hosts% smtp transport option performs the
+The &%tls_resumption_hosts%& smtp transport option performs the
 equivalent function for operation as a client.
 If the peer host matches the list after expansion then resumption
 is attempted (if a stored session is available) or the information