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%&"
.code
dns_again_means_nonexist = *.in-addr.arpa
.endd
-This option applies to all DNS lookups that Exim does. It also applies when the
+This option applies to all DNS lookups that Exim does,
+.new
+except for TLSA lookups (where knowing about such failures
+is security-relevant).
+.wen
+It also applies when the
&[gethostbyname()]& or &[getipnodebyname()]& functions give temporary errors,
since these are most likely to be caused by DNS lookup problems. The
&(dnslookup)& router has some options of its own for controlling what happens
acceptable bound from 1024 to 2048.
-.option tls_eccurve main string&!! &`auto`&
+.option tls_eccurve main string list&!! &`auto`&
.cindex TLS "EC cryptography"
-This option selects a EC curve for use by Exim when used with OpenSSL.
-It has no effect when Exim is used with GnuTLS.
+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
+&%tls_require_ciphers%& option).
-After expansion it must contain a valid EC curve parameter, such as
-&`prime256v1`&, &`secp384r1`&, or &`P-512`&. Consult your OpenSSL manual
-for valid selections.
+After expansion it must contain
+.new
+one or (only for OpenSSL versiona 1.1.1 onwards) more
+.wen
+EC curve names, such as &`prime256v1`&, &`secp384r1`&, or &`P-521`&.
+Consult your OpenSSL manual for valid curve names.
For OpenSSL versions before (and not including) 1.0.2, the string
&`auto`& selects &`prime256v1`&. For more recent OpenSSL versions
&`auto`& tells the library to choose.
-If the option expands to an empty string, no EC curves will be enabled.
+.new
+If the option expands to an empty string, the effect is undefined.
+.wen
.option tls_ocsp_file main string&!! unset
resent to other recipients.
&*Note:*& If used on a transport handling multiple recipients
-(the smtp transport unless &%rcpt_max%& is 1, the appendfile, pipe or lmtp
+(the smtp transport unless &%max_rcpt%& is 1, the appendfile, pipe or lmtp
transport if &%batch_max%& is greater than 1)
then information about Bcc recipients will be leaked.
Doing so is generally not advised.
string &`IGNOREQUOTA`& is added to RCPT commands, provided that the LMTP server
has advertised support for IGNOREQUOTA in its response to the LHLO command.
-.option max_rcpt smtp integer 100
+.option max_rcpt smtp integer&!! 100
.cindex "RCPT" "maximum number of outgoing"
-This option limits the number of RCPT commands that are sent in a single
-SMTP message transaction. Each set of addresses is treated independently, and
+This option,
+.new
+after expansion,
+.wen
+limits the number of RCPT commands that are sent in a single
+SMTP message transaction.
+A value setting of zero disables the limit.
+
+.new
+If a constant is given,
+.wen
+each set of addresses is treated independently, and
so can cause parallel connections to the same host if &%remote_max_parallel%&
-permits this. A value setting of zero disables the limit.
+permits this.
.option message_linelength_limit smtp integer 998