+DCC Support
+--------------------------------------------------------------
+
+*) Building exim
+
+In order to build exim with DCC support add
+
+EXPERIMENTAL_DCC=yes
+
+to your Makefile. (Re-)build/install exim. exim -d should show
+EXPERIMENTAL_DCC under "Support for".
+
+
+*) Configuration
+
+In the main section of exim.cf add at least
+ dccifd_address = /usr/local/dcc/var/dccifd
+or
+ dccifd_address = <ip> <port>
+
+In the DATA ACL you can use the new condition
+ dcc = *
+
+After that "$dcc_header" contains the X-DCC-Header.
+
+Returnvalues are:
+ fail for overall "R", "G" from dccifd
+ defer for overall "T" from dccifd
+ accept for overall "A", "S" from dccifd
+
+dcc = */defer_ok works as for spamd.
+
+The "$dcc_result" variable contains the overall result from DCC
+answer. There will an X-DCC: header added to the mail.
+
+Usually you'll use
+ defer !dcc = *
+to greylist with DCC.
+
+If you set, in the main section,
+ dcc_direct_add_header = true
+then the dcc header will be added "in deep" and if the spool
+file was already written it gets removed. This forces Exim to
+write it again if needed. This helps to get the DCC Header
+through to eg. SpamAssassin.
+
+If you want to pass even more headers in the middle of the
+DATA stage you can set
+ $acl_m_dcc_add_header
+to tell the DCC routines add more information; eg, you might set
+this to some results from ClamAV. Be careful. Header syntax is
+not checked and is added "as is".
+
+DBL (Database Logging)
+--------------------------------------------------------------
+
+This feature allows to write exim internal log information
+(not available otherwise) into a database.
+Initially implemented is logging of details about successfully
+completed remote deliveries, which are needed for reputation
+systems, and deferrals caused by a host error.
+
+In order to use DBL, you must set
+
+EXPERIMENTAL_DBL=yes
+
+in your Local/Makefile
+
+and define the database queries in the runtime config file, to
+be executed at end of delivery.
+
+Additionally, there are 8 more variables, available at end of
+delivery:
+
+dbl_delivery_ip IP of host, which has accepted delivery
+dbl_delivery_port Port of remote host which has accepted delivery
+dbl_delivery_fqdn FQDN of host, which has accepted delivery
+dbl_delivery_local_part local part of address being delivered
+dbl_delivery_domain domain part of address being delivered
+dbl_delivery_confirmation SMTP confirmation message
+
+In case of a deferral caused by a host-error:
+dbl_defer_errno Error number
+dbl_defer_errstr Error string possibly containing more details
+
+
+To log successful deliveries, set the following option in the main
+option part of runtime config.
+
+dbl_delivery_query
+
+An example might look like:
+
+dbl_delivery_query = \
+${lookup pgsql {SELECT * FROM record_Delivery( \
+ '${quote_pgsql:$sender_address_domain}',\
+ '${quote_pgsql:${lc:$sender_address_local_part}}', \
+ '${quote_pgsql:$dbl_delivery_domain}', \
+ '${quote_pgsql:${lc:$dbl_delivery_local_part}}', \
+ '${quote_pgsql:$dbl_delivery_ip}', \
+ '${quote_pgsql:${lc:$dbl_delivery_fqdn}}', \
+ '${quote_pgsql:$message_exim_id}')}}
+
+
+In order to log host deferrals, add the following option to an SMTP
+transport:
+
+dbl_host_defer_query
+
+This is a private option of the SMTP transport. It is intended to
+log failures of remote hosts. It is executed only when exim has
+attempted to deliver a message to a remote host and failed due to
+an error which doesn't seem to be related to the individual
+message, sender, or recipient address.
+See section 45.2 of the exim documentation for more details on how
+this is determined.
+
+Example:
+
+dbl_host_defer_query = \
+${lookup mysql {insert into delivlog set \
+ msgid = '${quote_mysql:$message_exim_id}', \
+ senderlp = '${quote_mysql:${lc:$sender_address_local_part}}', \
+ senderdom = '${quote_mysql:$sender_address_domain}', \
+ delivlp = '${quote_mysql:${lc:$dbl_delivery_local_part}}', \
+ delivdom = '${quote_mysql:$dbl_delivery_domain}', \
+ delivip = '${quote_mysql:$dbl_delivery_ip}', \
+ delivport = '${quote_mysql:$dbl_delivery_port}', \
+ delivfqdn = '${quote_mysql:$dbl_delivery_fqdn}', \
+ deliverrno = '${quote_mysql:$dbl_defer_errno}', \
+ deliverrstr = '${quote_mysql:$dbl_defer_errstr}' \
+ }}
+