diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/doc-docbook/spec.xfpt | 34 |
1 files changed, 23 insertions, 11 deletions
diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt index 7c34bbbc7..e512f2b4a 100644 --- a/doc/doc-docbook/spec.xfpt +++ b/doc/doc-docbook/spec.xfpt @@ -5557,16 +5557,21 @@ unreachable. The next two lines are concerned with &'ident'& callbacks, as defined by RFC 1413 (hence their names): .code -rfc1413_hosts = * -rfc1413_query_timeout = 5s +rfc1413_query_hosts = * +rfc1413_query_timeout = 0s +.endd +These settings cause Exim to avoid ident callbacks for all incoming SMTP calls. +Few hosts offer RFC1413 service these days; calls have to be +terminated by a timeout and this needlessly delays the startup +of an incoming SMTP connection. +If you have hosts for which you trust RFC1413 and need this +information, you can change this. + +This line enables an efficiency SMTP option. It is negociated by clients +and not expected to cause problems but can be disabled if needed. +.code +prdr_enable = true .endd -These settings cause Exim to make ident callbacks for all incoming SMTP calls. -You can limit the hosts to which these calls are made, or change the timeout -that is used. If you set the timeout to zero, all ident calls are disabled. -Although they are cheap and can provide useful information for tracing problem -messages, some hosts and firewalls have problems with ident calls. This can -result in a timeout instead of an immediate refused connection, leading to -delays on starting up an incoming SMTP session. When Exim receives messages over SMTP connections, it expects all addresses to be fully qualified with a domain, as required by the SMTP definition. However, @@ -6002,9 +6007,14 @@ One remote transport and four local transports are defined. .code remote_smtp: driver = smtp + hosts_try_prdr = * .endd -This transport is used for delivering messages over SMTP connections. All its -options are defaulted. The list of remote hosts comes from the router. +This transport is used for delivering messages over SMTP connections. +The list of remote hosts comes from the router. +The &%hosts_try_prdr%& option enables an efficiency SMTP option. +It is negotiated between client and server +and not expected to cause problems but can be disabled if needed. +All other options are defaulted. .code local_delivery: driver = appendfile @@ -26663,6 +26673,8 @@ See also the &%prdr_enable%& global option and the &%hosts_try_prdr%& smtp transport option. This ACL is evaluated after &%acl_smtp_dkim%& but before &%acl_smtp_data%&. +If the ACL is not defined, processing completes as if +the feature was not requested by the client. .section "The QUIT ACL" "SECTQUITACL" .cindex "QUIT, ACL for" |