postfix-2.0.16-20040105

postfix/HISTORY

@@ -8978,13 +8978,13 @@ Apologies for any names omitted.
 	used by the Postfix SMTP server. Liviu Daia. Files:
 	mail_params.h, smtpd.c, smtpd_sasl_glue.c.
 
-	Cleanup: shared config file parser for ldap, mysql, pgsql
+	Cleanup: the LDAP client configuration parser is now shared
-	lookup tables. Liviu Daia. Files: global/cfgparser.[hc],
+	between the LDAP, MySQL, and PGSQL clients.  Liviu Daia.
-	global/dict_ldap.c, global/dict_mtsql.c, global/dict_pgsql.c
+	Files: global/cfgparser.[hc], global/dict_ldap.c,
-	and documentation.
+	global/dict_mtsql.c, global/dict_pgsql.c and documentation.
 
-	Cleanup: moved modules with dependencies on higher-level
+	Cleanup: moved "util" modules with dependencies on higher-level
-	code from the util directory to the global directory:
+	"global" code from the util directory to the global directory:
 	util/dict_open.c, global/cfgparser.[hc], global/dict_ldap.c,
 	global/dict_mtsql.c, global/dict_pgsql.c, global/mail_dict.c.
 
@@ -8998,6 +8998,19 @@ Apologies for any names omitted.
 	character stored.  This avoids mis-leading warnings. File:
 	global/vstring_vstream.c.
 
+20040105
+
+	Cleanup: don't bother the flush daemon while deferring mail
+	if the destination is not "fast flush" eligible. File:
+	global/flush_clnt.c.
+
+	Safety: the SMTP server flushes recipients to the cleanup
+	server in order to avoid SMTP timeouts when virtual or
+	canonical expansions take a lot of time. File smtpd/smtpd.c.
+
+	Safety: add warnings to postmap and postalias when table
+	lookup results in an empty string.
+
 Open problems:
 
 	Low: in the SMTP client, pass the session, request and

postfix/README_FILES/FILTER_README

@@ -314,7 +314,7 @@ filtering for incoming mail. This is required or else mail will
 stay in the content filtering loop.
 
 The "-o receive_override_options" overrides main.cf. It is
-complementary to the the options that are specified in main.cf:
+complementary to the options that are specified in main.cf:
 
 - Disable attempts to find out if a recipient is unknown, and
   disable header/body checks. This work was already done before

postfix/README_FILES/VIRTUAL_MAILBOX_README

@@ -2,6 +2,9 @@ This code was created by Andrew McNamara <andrew@connect.com.au>
 and adapted to snapshot 20001121 by Xavier Beaudouin. It was merged
 with mainstream Postfix for snapshot 20010128 by Wietse.
 
+See the VIRTUAL_README file for an overview of how you can host
+multiple domains with one Postfix system.
+
 Purpose of this software
 ========================
 

postfix/README_FILES/VIRTUAL_README

@@ -1,17 +1,258 @@
-Porpose of this document
+Purpose of this document
 ========================
 
-Hosting multiple domains on one server
+This document describes how to configure one Postfix system for
+final mail delivery of multiple Internet domains, using the mailbox
+and maildir delivery mechanisms that are already built into Postfix.
 
+See the LMTP_README file for an example of final delivery with
+third-party mailstores such as Cyrus.
 
-UNIX system accounts, domain shared with all users
+Preliminaries: local files versus databases
-==================================================
+===========================================
 
-UNIX system accounts, domains not shared
+The examples in this text use table lookups from local files.
-========================================
+These are easy to debug with the postmap "-q" command option.
 
-Non-UNIX accounts, domains not shared
+Example: postmap -q info@example.com hash:/etc/postfix/virtual
-=====================================
+
+See LDAP_README, MYSQL_README and PGSQL_README for how to replace
+local files by databases. The reader is strongly advised to make
+the system work with local files before migrating to database files,
+and to use the postmap "-q" command option to verify that database
+lookups produce the exact same results as local file lookup.
+
+Example: postmap -q info@example.com:ldap:/etc/postfix/virtual.cf
+
+Preliminaries: canonical versus virtual domains
+===============================================
+
+Each Postfix system does final delivery for a small number of
+canonical domains; usually these are the names of the machine that
+Postfix runs on. Sometimes the list of canonical domains also
+includes the parent domain of the machine name.
+
+Postfix can be configured to do final delivery for additional
+domains.  The domains are called virtual, because they are not
+associated with the name of the machine itself.
+
+Postfix understands two types of virtual domain:
+
+- The virtual alias domain, where each virtual address is aliased
+  to a different (remote or local) address.
+
+- The virtual mailbox domain, where each virtual address can have
+  its own mailbox.
+
+A third type, the "sendmail style virtual domain" was described
+with older Postfix versions. It will not be discussed here in order
+to avoid a lot of confusion.
+
+Shared domains, UNIX system accounts
+====================================
+
+The simplest method to host an additional domain is to specify the
+user names in the UNIX password file and to specify the domain name
+in the Postfix mydestination configuration parameter.
+
+In the examples we will use "example.com" as the domain that is
+being hosted on the local Postfix machine.
+
+/etc/postfix/main.cf:
+    mydestination = $myhostname localhost.$mydomain ... example.com
+
+The downside of this approach is a total lack of separation: mail
+for info@my.host.name is delivered to the same UNIX system account
+as mail for info@example.com.  If different domains need to have
+different "info" mailboxes, then you can use one of the methods
+described in the remainder of this document.
+
+Another downside of listing all users in the UNIX password file is
+that administration of large numbers of users becomes inconvenient.
+
+Virtual ALIAS domains: separate domains, UNIX system accounts
+=============================================================
+
+The simplest method to host separate domains is to create so-called
+virtual aliases that redirect mail from each virtual address to
+its own UNIX account.
+
+The example below shows how to set up the example.com domain
+as a so-called virtual alias domain:
+
+/etc/postfix/main.cf:
+    virtual_alias_domains = example.com ...other domains...
+    virtual_alias_maps = hash:/etc/postfix/virtual
+
+/etc/postfix/virtual:
+    postmaster@example.com postmaster
+    info@example.com       joe
+    sales@example.com      jane
+    # Uncomment entry below to implement a catch-all address
+    # @example.com         jim
+    ...virtual aliases for other domains...
+
+The virtual_alias_domains setting tells Postfix that example.com
+is a so-called virtual alias domain. If you omit this step then
+Postfix will either reject mail (relay access denied) or will not
+be able to deliver it (mail for example.com loops back to myself).
+
+The /etc/postfix/virtual file contains the virtual aliases. With
+the example above, mail for postmaster@example.com goes to the
+local postmaster, while mail for info@example.com goes to the UNIX
+account joe, and mail for sales@example.com goes to the UNIX account
+jane.  Mail for all other addresses in example.com is rejected with
+the error message "User unknown".
+
+The commented out entry (text after #) shows how one would implement
+a catch-all virtual alias that receives mail for every example.com
+address not listed in the virtual alias file. This is not without
+risk.  Spammers nowadays try to send mail from (or mail to) every
+possible name that they can think of. A catch-all mailbox is likely
+to receive many spam messages, and many bounces for spam messages
+that were sent in the name of anything@example.com.
+
+Execute the command "postmap /etc/postfix/virtual" after changing
+the virtual file, and execute the command "postfix reload" after
+changing the main.cf file.
+
+Note: virtual aliases can resolve to a local address or to a remote
+address, or both.  They don't have to resolve to UNIX system accounts
+on your machine.
+
+More details about the virtual alias file are given in the virtual(5)
+manual page, including multiple addresses on the right-hand side.
+
+Virtual aliasing solves one problem: it allows each domain to have
+its own info mail address.  Virtual aliasing to UNIX system accounts
+still has the drawback that every user has to be listed in the UNIX
+password file.  The next section eliminates this problem.
+
+Virtual MAILBOX domains: separate domains, non-UNIX accounts
+============================================================
+
+As a system hosts more and more domains and users, it becomes
+unpractical to give everyone their own UNIX system account.
+
+With the Postfix virtual delivery agent, every recipient address
+can have its own virtual mailbox. Unlike virtual alias domains,
+there is no translation from recipient addresses into different
+addresses.
+
+The Postfix virtual delivery agent looks up the user mailbox
+pathname, uid and gid via separate tables that are searched with
+the recipient's mail address. Maildir style delivery is turned on
+by terminating the mailbox pathname with "/".
+
+Here is an example of a virtual mailbox domain example.com:
+
+/etc/postfix/main.cf:
+    virtual_mailbox_base = /var/mail/vhosts
+    virtual_mailbox_maps = hash:/etc/postfix/vmailbox
+    virtual_mailbox_domains = example.com ...other domains...
+    virtual_minimum_uid = 100
+    virtual_uid_maps = static:5000
+    virtual_gid_maps = static:5000
+    virtual_alias_maps = hash:/etc/postfix/virtual
+
+/etc/postfix/vmailbox:
+    info@example.com    example.com/info
+    sales@example.com   example.com/sales/
+    # Comment out the entry below to implement a catch-all.
+    # @example.com      example.com/catchall
+    ...virtual mailboxes for other domains...
+
+/etc/postfix/virtual:
+    postmaster@example.com postmaster
+
+The virtual_mailbox_base parameter specifies a prefix for all
+virtual mailbox pathnames. This is a safety mechanism that prevents
+mail from being delivered all over the file system.
+
+The virtual_mailbox_maps parameter specifies the lookup table with
+mailbox (or maildir) pathnames, indexed by the virtual mail address.
+In this example, mail for info@example.com goes to the mailbox at
+/var/mail/vhosts/example.com/info while mail for sales@example.com
+goes to the maildir located at /var/mail/vhosts/example.com/sales/.
+
+The virtual_minimum_uid prevents specifies a lower bound on the
+mailbox or maildir owner's UID.  This is a safety mechanism that
+prevents mail from being written to sensitive files.
+
+In the above example, the virtual_uid_maps and virtual_gid_maps
+parameters specify that all the virtual mailboxes are owned by a
+fixed uid and gid 5000.  If this is not what you want, specify
+lookup tables that are searched by the recipient's mail address.
+
+The commented out entry (text after #) shows how one would implement
+a catch-all virtual mailbox address. Be prepared to receive a lot
+of spam, as well as bounced spam that was sent in the name of
+anything@example.com.
+
+NEVER put a virtual MAILBOX wild-card in the virtual ALIAS file!!
+
+As you see above, it is possible to mix virtual aliases with virtual
+mailboxes. We use this feature to redirect mail for example.com's
+postmaster address to the local postmaster.
+
+Execute the command "postmap /etc/postfix/virtual" after changing
+the virtual file, execute "postmap /etc/postfix/vmailbox" after
+changing the vmailbox file, and execute the command "postfix reload"
+after changing the main.cf file.
+
+Note: mail delivery happens with the UID/GID privileges of the
+recipient. You must create maildirs in advance before you can use
+them. Depending on directory permissions, Postfix may be able to
+create mailbox files  by itself, but it is safer to create them
+ahead of time.
+
+More details about the virtual mailbox delivery agent are given
+in the file VIRTUAL_MAILBOX_README, and in the virtual(8) manual
+page.
 
 Aliases, mailing lists, etc.
 ============================
+
+The examples above already show how to direct mail for virtual
+postmaster addresses to a local postmaster. The same method can be
+used to direct mail for other virtual addresses to a local or remote
+address.
+
+Virtual aliases can't directly deliver to mailing list managers
+such as majordomo. One solution is to set up a transport mapping
+that directs the mail to the Postfix local delivery agent, and to
+use the local alias file for delivery to the mailing list manager:
+
+/etc/postfix/main.cf:
+    transport_maps = hash:/etc/postfix/transport
+
+/etc/postfix/transport:
+    listname-request@example.com local:
+    listname@example.com         local:
+    owner-listname@example.com   local:
+
+/etc/aliases:
+    listname: "|/some/where/majordomo/wrapper ..."
+    owner-listname: ...
+    listname-request: ...
+
+You can achieve the same result with virtual aliases that direct
+virtual addresses to the local delivery agent:
+
+/etc/postfix/main.cf:
+    virtual_alias_maps = hash:/etc/postfix/virtual
+
+/etc/postfix/virtual:
+    listname-request@example.com listname-request
+    listname@example.com         listname
+    owner-listname@example.com   owner-listname
+
+/etc/aliases:
+    listname: "|/some/where/majordomo/wrapper ..."
+    owner-listname: ...
+    listname-request: ...
+
+Either approach will do the job.
+
+More information about the Postfix local delivery agent can be
+found in the local(8) manual page.

postfix/html/postmap.1.html

@@ -1,4 +1,4 @@
-<html> <head> </head> <body> <pre>
+<html> <body> <pre>
 POSTMAP(1)                                             POSTMAP(1)
 
 <b>NAME</b>

postfix/makedefs

@@ -336,7 +336,7 @@ AR	= $AR
 ARFL	= $ARFL
 RANLIB	= $RANLIB
 SYSLIBS	= $AUXLIBS $SYSLIBS
-CC	= $CC $CCARGS
+CC	= $CC -DSNAPSHOT $CCARGS
 OPT	= $OPT
 DEBUG	= $DEBUG
 AWK	= $AWK

postfix/src/cleanup/Makefile.in

@@ -245,6 +245,7 @@ cleanup_init.o: ../../include/name_mask.h
 cleanup_init.o: ../../include/mail_addr.h
 cleanup_init.o: ../../include/mail_params.h
 cleanup_init.o: ../../include/ext_prop.h
+cleanup_init.o: ../../include/flush_clnt.h
 cleanup_init.o: cleanup.h
 cleanup_init.o: ../../include/vstring.h
 cleanup_init.o: ../../include/vbuf.h

postfix/src/cleanup/cleanup_init.c

@@ -78,6 +78,7 @@
 #include <mail_addr.h>
 #include <mail_params.h>
 #include <ext_prop.h>
+#include <flush_clnt.h>
 
 /* Application-specific. */
 
@@ -244,6 +245,8 @@ void    cleanup_pre_jail(char *unused_name, char **unused_argv)
 	cleanup_rcpt_bcc_maps =
 	    maps_create(VAR_RCPT_BCC_MAPS, var_rcpt_bcc_maps,
 			DICT_FLAG_LOCK);
+
+    flush_init();
 }
 
 /* cleanup_post_jail - initialize after entering the chroot jail */

postfix/src/error/Makefile.in

@@ -63,4 +63,5 @@ error.o: ../../include/recipient_list.h
 error.o: ../../include/mail_queue.h
 error.o: ../../include/bounce.h
 error.o: ../../include/deliver_completed.h
+error.o: ../../include/flush_clnt.h
 error.o: ../../include/mail_server.h

postfix/src/error/error.c

@@ -81,6 +81,7 @@
 #include <mail_queue.h>
 #include <bounce.h>
 #include <deliver_completed.h>
+#include <flush_clnt.h>
 
 /* Single server skeleton. */
 
@@ -176,9 +177,18 @@ static void error_service(VSTREAM *client_stream, char *unused_service, char **a
     }
 }
 
+/* pre_init - pre-jail initialization */
+
+static void pre_init(char *unused_name, char **unused_argv)
+{
+    flush_init();
+}
+
 /* main - pass control to the single-threaded skeleton */
 
 int     main(int argc, char **argv)
 {
-    single_server_main(argc, argv, error_service, 0);
+    single_server_main(argc, argv, error_service,
+		       MAIL_SERVER_PRE_INIT, pre_init,
+		       0);
 }

postfix/src/global/flush_clnt.c

@@ -6,6 +6,8 @@
 /* SYNOPSIS
 /*	#include <flush_clnt.h>
 /*
+/*	void	flush_init()
+/*
 /*	int	flush_add(site, queue_id)
 /*	const char *site;
 /*	const char *queue_id;
@@ -22,6 +24,9 @@
 /*	is maintained for eligible destinations. A destination is the
 /*	right-hand side of a user@domain email address.
 /*
+/*	flush_init() initializes. It must be called before dropping
+/*	privileges in a daemon process.
+/*
 /*	flush_add() informs the "fast flush" cache manager that mail is
 /*	queued for the specified site with the specified queue ID.
 /*
@@ -77,13 +82,25 @@
 
 #include <mail_proto.h>
 #include <mail_flush.h>
-#include <flush_clnt.h>
 #include <mail_params.h>
+#include <domain_list.h>
+#include <match_parent_style.h>
+#include <flush_clnt.h>
 
 /* Application-specific. */
 
 #define STR(x)	vstring_str(x)
 
+static DOMAIN_LIST *flush_domains;
+
+/* flush_init - initialize */
+
+void    flush_init(void)
+{
+    flush_domains = domain_list_init(match_parent_style(VAR_FFLUSH_DOMAINS),
+				     var_fflush_domains);
+}
+
 /* flush_purge - house keeping */
 
 int     flush_purge(void)
@@ -147,9 +164,12 @@ int     flush_send(const char *site)
 	msg_info("%s: site %s", myname, site);
 
     /*
-     * Don't bother the server if the service is turned off.
+     * Don't bother the server if the service is turned off, or if the site
+     * is not eligible.
      */
-    if (*var_fflush_domains == 0)
+    if (flush_domains == 0)
+	msg_panic("missing flush client initialization");
+    if (domain_list_match(flush_domains, site) == 0)
 	status = FLUSH_STAT_DENY;
     else
 	status = mail_command_client(MAIL_CLASS_PUBLIC, var_flush_service,
@@ -174,9 +194,12 @@ int     flush_add(const char *site, const char *queue_id)
 	msg_info("%s: site %s id %s", myname, site, queue_id);
 
     /*
-     * Don't bother the server if the service is turned off.
+     * Don't bother the server if the service is turned off, or if the site
+     * is not eligible.
      */
-    if (*var_fflush_domains == 0)
+    if (flush_domains == 0)
+	msg_panic("missing flush client initialization");
+    if (domain_list_match(flush_domains, site) == 0)
 	status = FLUSH_STAT_DENY;
     else
 	status = mail_command_client(MAIL_CLASS_PUBLIC, var_flush_service,

postfix/src/global/flush_clnt.h

@@ -14,6 +14,7 @@
  /*
   * External interface.
   */
+extern void flush_init(void);
 extern int flush_add(const char *, const char *);
 extern int flush_send(const char *);
 extern int flush_refresh(void);

postfix/src/global/mail_version.h

@@ -20,7 +20,7 @@
   * Patches change the patchlevel and the release date. Snapshots change the
   * release date only, unless they include the same bugfix as a patch release.
   */
-#define MAIL_RELEASE_DATE	"20040104"
+#define MAIL_RELEASE_DATE	"20040105"
 
 #define VAR_MAIL_VERSION	"mail_version"
 #define DEF_MAIL_VERSION	"2.0.16-" MAIL_RELEASE_DATE

postfix/src/lmtp/Makefile.in

@@ -75,6 +75,7 @@ lmtp.o: ../../include/mail_params.h
 lmtp.o: ../../include/mail_conf.h
 lmtp.o: ../../include/debug_peer.h
 lmtp.o: ../../include/mail_error.h
+lmtp.o: ../../include/flush_clnt.h
 lmtp.o: ../../include/mail_server.h
 lmtp.o: lmtp.h
 lmtp.o: lmtp_sasl.h

postfix/src/lmtp/lmtp.c

@@ -253,6 +253,7 @@
 #include <mail_conf.h>
 #include <debug_peer.h>
 #include <mail_error.h>
+#include <flush_clnt.h>
 
 /* Single server skeleton. */
 
@@ -496,6 +497,11 @@ static void pre_init(char *unused_name, char **unused_argv)
 	msg_warn("%s is true, but SASL support is not compiled in",
 		 VAR_LMTP_SASL_ENABLE);
 #endif
+
+    /*
+     * flush client.
+     */
+    flush_init();
 }
 
 /* cleanup - close any open connections, etc. */

postfix/src/local/Makefile.in

@@ -310,6 +310,7 @@ local.o: ../../include/mail_conf.h
 local.o: ../../include/been_here.h
 local.o: ../../include/ext_prop.h
 local.o: ../../include/maps.h
+local.o: ../../include/flush_clnt.h
 local.o: ../../include/mail_server.h
 local.o: local.h
 local.o: ../../include/tok822.h

postfix/src/local/local.c

@@ -473,6 +473,7 @@
 #include <mail_params.h>
 #include <ext_prop.h>
 #include <maps.h>
+#include <flush_clnt.h>
 
 /* Single server skeleton. */
 
@@ -708,6 +709,8 @@ static void pre_init(char *unused_name, char **unused_argv)
     }
     alias_maps = maps_create("aliases", var_alias_maps,
 			     DICT_FLAG_LOCK | DICT_FLAG_PARANOID);
+
+    flush_init();
 }
 
 /* main - pass control to the single-threaded skeleton */

postfix/src/oqmgr/Makefile.in

@@ -74,6 +74,7 @@ qmgr.o: ../../include/mail_proto.h
 qmgr.o: ../../include/iostuff.h
 qmgr.o: ../../include/attr.h
 qmgr.o: ../../include/mail_flow.h
+qmgr.o: ../../include/flush_clnt.h
 qmgr.o: ../../include/master_proto.h
 qmgr.o: ../../include/mail_server.h
 qmgr.o: qmgr.h

postfix/src/oqmgr/qmgr.c

@@ -255,6 +255,7 @@
 #include <mail_params.h>
 #include <mail_proto.h>			/* QMGR_SCAN constants */
 #include <mail_flow.h>
+#include <flush_clnt.h>
 
 /* Master process interface */
 
@@ -437,6 +438,13 @@ static void pre_accept(char *unused_name, char **unused_argv)
     }
 }
 
+/* qmgr_pre_init - pre-jail initialization */
+
+static void qmgr_pre_init(char *unused_name, char **unused_argv)
+{
+    flush_init();
+}
+
 /* qmgr_post_init - post-jail initialization */
 
 static void qmgr_post_init(char *unused_name, char **unused_argv)
@@ -519,6 +527,7 @@ int     main(int argc, char **argv)
 			MAIL_SERVER_STR_TABLE, str_table,
 			MAIL_SERVER_BOOL_TABLE, bool_table,
 			MAIL_SERVER_TIME_TABLE, time_table,
+			MAIL_SERVER_PRE_INIT, qmgr_pre_init,
 			MAIL_SERVER_POST_INIT, qmgr_post_init,
 			MAIL_SERVER_LOOP, qmgr_loop,
 			MAIL_SERVER_PRE_ACCEPT, pre_accept,

postfix/src/pipe/Makefile.in

@@ -83,4 +83,5 @@ pipe.o: ../../include/split_addr.h
 pipe.o: ../../include/off_cvt.h
 pipe.o: ../../include/quote_822_local.h
 pipe.o: ../../include/quote_flags.h
+pipe.o: ../../include/flush_clnt.h
 pipe.o: ../../include/mail_server.h

postfix/src/pipe/pipe.c

@@ -279,6 +279,7 @@
 #include <split_addr.h>
 #include <off_cvt.h>
 #include <quote_822_local.h>
+#include <flush_clnt.h>
 
 /* Single server skeleton. */
 
@@ -998,6 +999,13 @@ static void drop_privileges(char *unused_name, char **unused_argv)
     set_eugid(var_owner_uid, var_owner_gid);
 }
 
+/* pre_init - initialize */
+
+static void pre_init(char *unused_name, char **unused_argv)
+{
+    flush_init();
+}
+
 /* main - pass control to the single-threaded skeleton */
 
 int     main(int argc, char **argv)
@@ -1009,6 +1017,7 @@ int     main(int argc, char **argv)
 
     single_server_main(argc, argv, pipe_service,
 		       MAIL_SERVER_TIME_TABLE, time_table,
+		       MAIL_SERVER_PRE_INIT, pre_init,
 		       MAIL_SERVER_POST_INIT, drop_privileges,
 		       MAIL_SERVER_PRE_ACCEPT, pre_accept,
 		       0);

postfix/src/postalias/postalias.c

@@ -397,6 +397,12 @@ static int postalias_queries(VSTREAM *in, char **maps, const int map_count,
 		   dict_open3(maps[n], map_name, O_RDONLY, DICT_FLAG_LOCK) :
 		dict_open3(var_db_type, maps[n], O_RDONLY, DICT_FLAG_LOCK));
 	    if ((value = dict_get(dicts[n], STR(keybuf))) != 0) {
+		if (*value == 0) {
+		    msg_warn("table %s:%s: key %s: empty string result is not allowed",
+			     dicts[n]->type, dicts[n]->name, STR(keybuf));
+		    msg_warn("table %s:%s should return NO RESULT in case of NOT FOUND",
+			     dicts[n]->type, dicts[n]->name);
+		}
 		vstream_printf("%s:	%s\n", STR(keybuf), value);
 		found = 1;
 		break;
@@ -428,6 +434,12 @@ static int postalias_query(const char *map_type, const char *map_name,
 
     dict = dict_open3(map_type, map_name, O_RDONLY, DICT_FLAG_LOCK);
     if ((value = dict_get(dict, key)) != 0) {
+	if (*value == 0) {
+	    msg_warn("table %s:%s: key %s: empty string result is not allowed",
+		     map_type, map_name, key);
+	    msg_warn("table %s:%s should return NO RESULT in case of NOT FOUND",
+		     map_type, map_name);
+	}
 	vstream_printf("%s\n", value);
 	vstream_fflush(VSTREAM_OUT);
     }

postfix/src/postmap/postmap.c

@@ -345,6 +345,12 @@ static int postmap_queries(VSTREAM *in, char **maps, const int map_count,
 		   dict_open3(maps[n], map_name, O_RDONLY, DICT_FLAG_LOCK) :
 		dict_open3(var_db_type, maps[n], O_RDONLY, DICT_FLAG_LOCK));
 	    if ((value = dict_get(dicts[n], STR(keybuf))) != 0) {
+		if (*value == 0) {
+		    msg_warn("table %s:%s: key %s: empty string result is not allowed",
+			     dicts[n]->type, dicts[n]->name, STR(keybuf));
+		    msg_warn("table %s:%s should return NO RESULT in case of NOT FOUND",
+			     dicts[n]->type, dicts[n]->name);
+		}
 		vstream_printf("%s	%s\n", STR(keybuf), value);
 		found = 1;
 		break;
@@ -376,6 +382,12 @@ static int postmap_query(const char *map_type, const char *map_name,
 
     dict = dict_open3(map_type, map_name, O_RDONLY, DICT_FLAG_LOCK);
     if ((value = dict_get(dict, key)) != 0) {
+	if (*value == 0) {
+	    msg_warn("table %s:%s: key %s: empty string result is not allowed",
+		     map_type, map_name, key);
+	    msg_warn("table %s:%s should return NO RESULT in case of NOT FOUND",
+		     map_type, map_name);
+	}
 	vstream_printf("%s\n", value);
 	vstream_fflush(VSTREAM_OUT);
     }

postfix/src/qmgr/Makefile.in

@@ -76,6 +76,7 @@ qmgr.o: ../../include/mail_proto.h
 qmgr.o: ../../include/iostuff.h
 qmgr.o: ../../include/attr.h
 qmgr.o: ../../include/mail_flow.h
+qmgr.o: ../../include/flush_clnt.h
 qmgr.o: ../../include/master_proto.h
 qmgr.o: ../../include/mail_server.h
 qmgr.o: qmgr.h

postfix/src/qmgr/qmgr.c

@@ -300,6 +300,7 @@
 #include <mail_params.h>
 #include <mail_proto.h>			/* QMGR_SCAN constants */
 #include <mail_flow.h>
+#include <flush_clnt.h>
 
 /* Master process interface */
 
@@ -485,6 +486,13 @@ static void pre_accept(char *unused_name, char **unused_argv)
     }
 }
 
+/* qmgr_pre_init - pre-jail initialization */
+
+static void qmgr_pre_init(char *unused_name, char **unused_argv)
+{
+    flush_init();
+}
+
 /* qmgr_post_init - post-jail initialization */
 
 static void qmgr_post_init(char *name, char **unused_argv)
@@ -583,6 +591,7 @@ int     main(int argc, char **argv)
 			MAIL_SERVER_STR_TABLE, str_table,
 			MAIL_SERVER_BOOL_TABLE, bool_table,
 			MAIL_SERVER_TIME_TABLE, time_table,
+			MAIL_SERVER_PRE_INIT, qmgr_pre_init,
 			MAIL_SERVER_POST_INIT, qmgr_post_init,
 			MAIL_SERVER_LOOP, qmgr_loop,
 			MAIL_SERVER_PRE_ACCEPT, pre_accept,

postfix/src/smtp/Makefile.in

@@ -75,6 +75,7 @@ smtp.o: ../../include/recipient_list.h
 smtp.o: ../../include/mail_params.h
 smtp.o: ../../include/mail_conf.h
 smtp.o: ../../include/debug_peer.h
+smtp.o: ../../include/flush_clnt.h
 smtp.o: ../../include/mail_server.h
 smtp.o: smtp.h
 smtp.o: smtp_sasl.h

postfix/src/smtp/smtp.c

@@ -282,6 +282,7 @@
 #include <mail_params.h>
 #include <mail_conf.h>
 #include <debug_peer.h>
+#include <flush_clnt.h>
 
 /* Single server skeleton. */
 
@@ -452,6 +453,11 @@ static void pre_init(char *unused_name, char **unused_argv)
 	msg_warn("%s is true, but SASL support is not compiled in",
 		 VAR_SMTP_SASL_ENABLE);
 #endif
+
+    /*
+     * Flush client.
+     */
+    flush_init();
 }
 
 /* pre_accept - see if tables have changed */

postfix/src/smtpd/smtpd.c

@@ -469,6 +469,7 @@
 #include <namadr_list.h>
 #include <input_transp.h>
 #include <anvil_clnt.h>
+#include <flush_clnt.h>
 
 /* Single-threaded server skeleton. */
 
@@ -1266,12 +1267,17 @@ static int rcpt_cmd(SMTPD_STATE *state, int argc, SMTPD_TOKEN *argv)
 
     /*
      * Store the recipient. Remember the first one.
+     * 
+     * Flush recipients to maintain a stiffer coupling with the next stage and
+     * to better utilize parallelism.
      */
     state->rcpt_count++;
     if (state->recipient == 0)
 	state->recipient = mystrdup(argv[2].strval);
-    if (state->cleanup)
+    if (state->cleanup) {
 	rec_fputs(state->cleanup, REC_TYPE_RCPT, argv[2].strval);
+	vstream_fflush(state->cleanup);
+    }
     smtpd_chat_reply(state, "250 Ok");
     return (0);
 }
@@ -2396,6 +2402,11 @@ static void pre_jail_init(char *unused_name, char **unused_argv)
 	msg_warn("%s is true, but SASL support is not compiled in",
 		 VAR_SMTPD_SASL_ENABLE);
 #endif
+
+    /*
+     * flush client.
+     */
+    flush_init();
 }
 
 /* post_jail_init - post-jail initialization */

postfix/src/util/dict_open.c

@@ -191,7 +191,9 @@ typedef struct {
 static DICT_OPEN_INFO dict_open_info[] = {
     DICT_TYPE_ENVIRON, dict_env_open,
     DICT_TYPE_UNIX, dict_unix_open,
+#ifdef SNAPSHOT
     DICT_TYPE_TCP, dict_tcp_open,
+#endif
 #ifdef HAS_DBM
     DICT_TYPE_DBM, dict_dbm_open,
 #endif

postfix/src/virtual/Makefile.in

@@ -162,6 +162,7 @@ virtual.o: ../../include/mail_params.h
 virtual.o: ../../include/mail_conf.h
 virtual.o: ../../include/mail_addr_find.h
 virtual.o: ../../include/maps.h
+virtual.o: ../../include/flush_clnt.h
 virtual.o: ../../include/mail_server.h
 virtual.o: virtual.h
 virtual.o: ../../include/mbox_conf.h

postfix/src/virtual/virtual.c

@@ -312,6 +312,7 @@
 #include <mail_conf.h>
 #include <mail_params.h>
 #include <mail_addr_find.h>
+#include <flush_clnt.h>
 
 /* Single server skeleton. */
 
@@ -476,6 +477,11 @@ static void pre_init(char *unused_name, char **unused_argv)
 		      VAR_VIRT_MAILBOX_LIMIT, VAR_MESSAGE_LIMIT);
 	set_file_limit(var_virt_mailbox_limit);
     }
+
+    /*
+     * flush client.
+     */
+    flush_init();
 }
 
 /* main - pass control to the single-threaded skeleton */