given.
Normally the daemon creates this socket, unless a &%-oX%& and &*no*& &%-oP%&
option is also present.
-If this option is given then the socket will not be created. This could be
-required if the system is running multiple daemons.
+.new
+If this option is given then the socket will not be created. This is required
+if the system is running multiple daemons, in which case it should
+be used on all.
+The features supported by the socket will not be available in such cases.
The socket is currently used for
.ilist
fast ramp-up of queue runner processes
.next
+caching compiled regexes
+.next
obtaining a current queue size
.endlist
+.wen
.cmdopt -pd
.cindex "Perl" "starting the interpreter"
transports are run.
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,
+If that is so and
+the &%queue_fast_ramp%& option is true
+and a daemon-notifier socket is available
+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.
.cindex "hints database" "remembering routing"
The hints database that remembers which messages are waiting for specific hosts
-is updated, as if delivery to those hosts had been deferred. After this is
-complete, a second, normal queue scan happens, with routing and delivery taking
-place as normal. Messages that are routed to the same host should mostly be
+is updated, as if delivery to those hosts had been deferred.
+
+After the first queue scan complete,
+a second, normal queue scan is done, with routing and delivery taking
+place as normal.
+Messages that are routed to the same host should mostly be
delivered down a single SMTP
.cindex "SMTP" "passed connection"
.cindex "SMTP" "multiple deliveries"
.cindex "multiple SMTP deliveries"
connection because of the hints that were set up during the first queue scan.
-This option may be useful for hosts that are connected to the Internet
+
+.new
+Two-phase queue runs should be used on systems which, even intermittently,
+have a large queue (such as mailing-list operators).
+They may also be useful for hosts that are connected to the Internet
intermittently.
+.wen
.vitem &%-q[q]i...%&
.oindex "&%-qi%&"
.cindex TLS "EC cryptography"
This option selects EC curves for use by Exim when used with OpenSSL.
It has no effect when Exim is used with GnuTLS
- (the equivalent can be done using a priority string for the
+(the equivalent can be done using a priority string for the
&%tls_require_ciphers%& option).
After expansion it must contain