diff --git a/HISTORY b/HISTORY
index 73db63f..bfc98a1 100644
--- a/HISTORY
+++ b/HISTORY
@@ -13599,3 +13599,9 @@ Apologies for any names omitted.
 	prevent dovecot-auth memory wastage. Timo Sirainen.  File:
 	xsasl/xsasl_dovecot_server.c.
 
+20080725
+
+	Paranoia: defer delivery when a mailbox file is not owned
+	by the recipient. Requested by Sebastian Krahmer, SuSE.
+	Specify "strict_mailbox_ownership=no" to ignore ownership
+	discrepancies.  Files: local/mailbox.c, virtual/mailbox.c.
diff --git a/RELEASE_NOTES b/RELEASE_NOTES
index cf371e5..fb5f4cd 100644
--- a/RELEASE_NOTES
+++ b/RELEASE_NOTES
@@ -11,6 +11,14 @@ instead, a new snapshot is released.
 The mail_release_date configuration parameter (format: yyyymmdd)
 specifies the release date of a stable release or snapshot release.
 
+Incompatibility with Postfix 2.4.7
+==================================
+
+When a mailbox file is not owned by its recipient, the local and
+virtual delivery agents now log a warning and defer delivery.
+Specify "strict_mailbox_ownership = no" to ignore such ownership
+discrepancies.
+ 
 Incompatibility with Postfix 2.4.4
 ==================================
 
diff --git a/html/local.8.html b/html/local.8.html
index de3fd4f..9cece01 100644
--- a/html/local.8.html
+++ b/html/local.8.html
@@ -394,6 +394,12 @@ LOCAL(8)                                                              LOCAL(8)
               attempt; do not update  the  Delivered-To:  address
               while expanding aliases or .forward files.
 
+       Available in Postfix version 2.4.7-r1 and later:
+
+       <b><a href="postconf.5.html#strict_mailbox_ownership">strict_mailbox_ownership</a> (yes)</b>
+              Defer delivery when a mailbox file is not owned  by
+              its recipient.
+
 <b>DELIVERY METHOD CONTROLS</b>
        The  precedence  of <a href="local.8.html"><b>local</b>(8)</a> delivery methods from high to
        low is: aliases, .forward  files,  <a href="postconf.5.html#mailbox_transport_maps">mailbox_transport_maps</a>,
@@ -532,6 +538,12 @@ LOCAL(8)                                                              LOCAL(8)
               agent allows in $name expansions of $<a href="postconf.5.html#command_execution_directory">command_execu</a>-
               <a href="postconf.5.html#command_execution_directory">tion_directory</a>.
 
+       Available in Postfix version 2.4.7-r1 and later:
+
+       <b><a href="postconf.5.html#strict_mailbox_ownership">strict_mailbox_ownership</a> (yes)</b>
+              Defer  delivery when a mailbox file is not owned by
+              its recipient.
+
 <b>MISCELLANEOUS CONTROLS</b>
        <b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b>
               The  default  location  of  the Postfix <a href="postconf.5.html">main.cf</a> and
diff --git a/html/postconf.5.html b/html/postconf.5.html
index a19b6b3..7952563 100644
--- a/html/postconf.5.html
+++ b/html/postconf.5.html
@@ -11602,6 +11602,17 @@ This feature is available in Postfix 2.0 and later.
 
 </DD>
 
+<DT><b><a name="strict_mailbox_ownership">strict_mailbox_ownership</a>
+(default: yes)</b></DT><DD>
+
+<p> Defer delivery when a mailbox file is not owned by its recipient.
+The default setting is not backwards compatible.  </p>
+
+<p> This feature is available in Postfix 2.4.7-r1 and later. </p>
+
+
+</DD>
+
 <DT><b><a name="strict_mime_encoding_domain">strict_mime_encoding_domain</a>
 (default: no)</b></DT><DD>
 
diff --git a/html/virtual.8.html b/html/virtual.8.html
index 3d7e526..0341911 100644
--- a/html/virtual.8.html
+++ b/html/virtual.8.html
@@ -200,9 +200,15 @@ VIRTUAL(8)                                                          VIRTUAL(8)
               destination  for  final  delivery to domains listed
               with $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>.
 
+       Available in Postfix version 2.4.7-r1 and later:
+
+       <b><a href="postconf.5.html#strict_mailbox_ownership">strict_mailbox_ownership</a> (yes)</b>
+              Defer delivery when a mailbox file is not owned  by
+              its recipient.
+
 <b>LOCKING CONTROLS</b>
        <b><a href="postconf.5.html#virtual_mailbox_lock">virtual_mailbox_lock</a> (see 'postconf -d' output)</b>
-              How to lock a UNIX-style <a href="virtual.8.html"><b>virtual</b>(8)</a> mailbox  before
+              How  to lock a UNIX-style <a href="virtual.8.html"><b>virtual</b>(8)</a> mailbox before
               attempting delivery.
 
        <b><a href="postconf.5.html#deliver_lock_attempts">deliver_lock_attempts</a> (20)</b>
@@ -210,41 +216,41 @@ VIRTUAL(8)                                                          VIRTUAL(8)
               sive lock on a mailbox file or <a href="bounce.8.html"><b>bounce</b>(8)</a> logfile.
 
        <b><a href="postconf.5.html#deliver_lock_delay">deliver_lock_delay</a> (1s)</b>
-              The time between attempts to acquire  an  exclusive
+              The  time  between attempts to acquire an exclusive
               lock on a mailbox file or <a href="bounce.8.html"><b>bounce</b>(8)</a> logfile.
 
        <b><a href="postconf.5.html#stale_lock_time">stale_lock_time</a> (500s)</b>
-              The  time  after  which  a  stale exclusive mailbox
+              The time after  which  a  stale  exclusive  mailbox
               lockfile is removed.
 
 <b>RESOURCE AND RATE CONTROLS</b>
        <b><a href="postconf.5.html#virtual_destination_concurrency_limit">virtual_destination_concurrency_limit</a>   ($<a href="postconf.5.html#default_destination_concurrency_limit">default_destina</a>-</b>
        <b><a href="postconf.5.html#default_destination_concurrency_limit">tion_concurrency_limit</a>)</b>
-              The maximal number of parallel  deliveries  to  the
-              same  destination  via the virtual message delivery
+              The  maximal  number  of parallel deliveries to the
+              same destination via the virtual  message  delivery
               transport.
 
        <b><a href="postconf.5.html#virtual_destination_recipient_limit">virtual_destination_recipient_limit</a>     ($<a href="postconf.5.html#default_destination_recipient_limit">default_destina</a>-</b>
        <b><a href="postconf.5.html#default_destination_recipient_limit">tion_recipient_limit</a>)</b>
-              The maximal number of recipients per  delivery  via
+              The  maximal  number of recipients per delivery via
               the virtual message delivery transport.
 
        <b><a href="postconf.5.html#virtual_mailbox_limit">virtual_mailbox_limit</a> (51200000)</b>
-              The  maximal size in bytes of an individual mailbox
+              The maximal size in bytes of an individual  mailbox
               or maildir file, or zero (no limit).
 
 <b>MISCELLANEOUS CONTROLS</b>
        <b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b>
-              The default location of  the  Postfix  <a href="postconf.5.html">main.cf</a>  and
+              The  default  location  of  the Postfix <a href="postconf.5.html">main.cf</a> and
               <a href="master.5.html">master.cf</a> configuration files.
 
        <b><a href="postconf.5.html#daemon_timeout">daemon_timeout</a> (18000s)</b>
-              How  much time a Postfix daemon process may take to
-              handle a request  before  it  is  terminated  by  a
+              How much time a Postfix daemon process may take  to
+              handle  a  request  before  it  is  terminated by a
               built-in watchdog timer.
 
        <b><a href="postconf.5.html#delay_logging_resolution_limit">delay_logging_resolution_limit</a> (2)</b>
-              The  maximal  number  of  digits  after the decimal
+              The maximal number  of  digits  after  the  decimal
               point when logging sub-second delay values.
 
        <b><a href="postconf.5.html#ipc_timeout">ipc_timeout</a> (3600s)</b>
@@ -252,33 +258,33 @@ VIRTUAL(8)                                                          VIRTUAL(8)
               over an internal communication channel.
 
        <b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
-              The  maximum  amount  of  time that an idle Postfix
-              daemon process waits  for  an  incoming  connection
+              The maximum amount of time  that  an  idle  Postfix
+              daemon  process  waits  for  an incoming connection
               before terminating voluntarily.
 
        <b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
-              The  maximal  number of incoming connections that a
-              Postfix daemon process will service  before  termi-
+              The maximal number of incoming connections  that  a
+              Postfix  daemon  process will service before termi-
               nating voluntarily.
 
        <b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
-              The  process  ID  of  a  Postfix  command or daemon
+              The process ID  of  a  Postfix  command  or  daemon
               process.
 
        <b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
-              The process name of a  Postfix  command  or  daemon
+              The  process  name  of  a Postfix command or daemon
               process.
 
        <b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
-              The  location of the Postfix top-level queue direc-
+              The location of the Postfix top-level queue  direc-
               tory.
 
        <b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
               The syslog facility of Postfix logging.
 
        <b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
-              The mail system  name  that  is  prepended  to  the
-              process  name  in  syslog  records, so that "smtpd"
+              The  mail  system  name  that  is  prepended to the
+              process name in syslog  records,  so  that  "smtpd"
               becomes, for example, "postfix/smtpd".
 
 <b>SEE ALSO</b>
@@ -291,20 +297,20 @@ VIRTUAL(8)                                                          VIRTUAL(8)
        <a href="VIRTUAL_README.html">VIRTUAL_README</a>, domain hosting howto
 
 <b>LICENSE</b>
-       The Secure Mailer license must be  distributed  with  this
+       The  Secure  Mailer  license must be distributed with this
        software.
 
 <b>HISTORY</b>
-       This  delivery  agent  was originally based on the Postfix
-       local delivery agent. Modifications  mainly  consisted  of
-       removing  code  that either was not applicable or that was
-       not safe in this context: aliases,  ~user/.forward  files,
+       This delivery agent was originally based  on  the  Postfix
+       local  delivery  agent.  Modifications mainly consisted of
+       removing code that either was not applicable or  that  was
+       not  safe  in this context: aliases, ~user/.forward files,
        delivery to "|command" or to /file/name.
 
        The <b>Delivered-To:</b> message header appears in the <b>qmail</b> sys-
        tem by Daniel Bernstein.
 
-       The <b>maildir</b> structure  appears  in  the  <b>qmail</b>  system  by
+       The  <b>maildir</b>  structure  appears  in  the  <b>qmail</b> system by
        Daniel Bernstein.
 
 <b>AUTHOR(S)</b>
diff --git a/man/man5/postconf.5 b/man/man5/postconf.5
index 7af763b..ba9f36a 100644
--- a/man/man5/postconf.5
+++ b/man/man5/postconf.5
@@ -7062,6 +7062,11 @@ This feature should not be enabled on a general purpose mail server,
 because it is likely to reject legitimate email.
 .PP
 This feature is available in Postfix 2.0 and later.
+.SH strict_mailbox_ownership (default: yes)
+Defer delivery when a mailbox file is not owned by its recipient.
+The default setting is not backwards compatible.
+.PP
+This feature is available in Postfix 2.4.7-r1 and later.
 .SH strict_mime_encoding_domain (default: no)
 Reject mail with invalid Content-Transfer-Encoding: information
 for the message/* or multipart/* MIME content types.  This blocks
diff --git a/man/man8/local.8 b/man/man8/local.8
index 4452007..5af15a9 100644
--- a/man/man8/local.8
+++ b/man/man8/local.8
@@ -412,6 +412,10 @@ Update the \fBlocal\fR(8) delivery agent's idea of the Delivered-To:
 address (see prepend_delivered_header) only once, at the start of
 a delivery attempt; do not update the Delivered-To: address while
 expanding aliases or .forward files.
+.PP
+Available in Postfix version 2.4.7-r1 and later:
+.IP "\fBstrict_mailbox_ownership (yes)\fR"
+Defer delivery when a mailbox file is not owned by its recipient.
 .SH "DELIVERY METHOD CONTROLS"
 .na
 .nf
@@ -510,7 +514,7 @@ Restrict \fBlocal\fR(8) mail delivery to external commands.
 Restrict \fBlocal\fR(8) mail delivery to external files.
 .IP "\fBcommand_expansion_filter (see 'postconf -d' output)\fR"
 Restrict the characters that the \fBlocal\fR(8) delivery agent allows in
-$name expansions of $mailbox_command.
+$name expansions of $mailbox_command and $command_execution_directory.
 .IP "\fBdefault_privs (nobody)\fR"
 The default rights used by the \fBlocal\fR(8) delivery agent for delivery
 to external file or command.
@@ -522,6 +526,10 @@ Available in Postfix version 2.2 and later:
 .IP "\fBexecution_directory_expansion_filter (see 'postconf -d' output)\fR"
 Restrict the characters that the \fBlocal\fR(8) delivery agent allows
 in $name expansions of $command_execution_directory.
+.PP
+Available in Postfix version 2.4.7-r1 and later:
+.IP "\fBstrict_mailbox_ownership (yes)\fR"
+Defer delivery when a mailbox file is not owned by its recipient.
 .SH "MISCELLANEOUS CONTROLS"
 .na
 .nf
diff --git a/man/man8/virtual.8 b/man/man8/virtual.8
index b45ac26..22e41b5 100644
--- a/man/man8/virtual.8
+++ b/man/man8/virtual.8
@@ -213,6 +213,10 @@ mail is delivered via the $virtual_transport mail delivery transport.
 .IP "\fBvirtual_transport (virtual)\fR"
 The default mail delivery transport and next-hop destination for
 final delivery to domains listed with $virtual_mailbox_domains.
+.PP
+Available in Postfix version 2.4.7-r1 and later:
+.IP "\fBstrict_mailbox_ownership (yes)\fR"
+Defer delivery when a mailbox file is not owned by its recipient.
 .SH "LOCKING CONTROLS"
 .na
 .nf
diff --git a/mantools/postlink b/mantools/postlink
index b4771d9..e2503ca 100755
--- a/mantools/postlink
+++ b/mantools/postlink
@@ -496,6 +496,7 @@ while (<>) {
     s;\bstrict_8bitmime\b;<a href="postconf.5.html#strict_8bitmime">$&</a>;g;
     s;\bstrict_8bitmime_body\b;<a href="postconf.5.html#strict_8bitmime_body">$&</a>;g;
     s;\bstrict_mime_encoding_domain\b;<a href="postconf.5.html#strict_mime_encoding_domain">$&</a>;g;
+    s;\bstrict_mailbox_ownership\b;<a href="postconf.5.html#strict_mailbox_ownership">$&</a>;g;
     s;\bstrict_rfc821_envelopes\b;<a href="postconf.5.html#strict_rfc821_envelopes">$&</a>;g;
     s;\bsun_mailtool_compatibility\b;<a href="postconf.5.html#sun_mailtool_compatibility">$&</a>;g;
     s;\bswap_bangpath\b;<a href="postconf.5.html#swap_bangpath">$&</a>;g;
diff --git a/proto/postconf.proto b/proto/postconf.proto
index f5a90ed..7761e7e 100644
--- a/proto/postconf.proto
+++ b/proto/postconf.proto
@@ -10586,3 +10586,10 @@ to the SASL authcid, but this causes inter-operability problems
 with some SMTP servers. </p>
 
 <p> This feature is available in Postfix 2.4.4 and later. </p>
+
+%PARAM strict_mailbox_ownership yes
+
+<p> Defer delivery when a mailbox file is not owned by its recipient.
+The default setting is not backwards compatible.  </p>
+
+<p> This feature is available in Postfix 2.4.7-r1 and later. </p>
diff --git a/src/global/mail_params.h b/src/global/mail_params.h
index 2785921..9cf6216 100644
--- a/src/global/mail_params.h
+++ b/src/global/mail_params.h
@@ -2783,6 +2783,13 @@ extern char *var_milt_v;
 #define DEF_INT_FILT_CLASSES		""
 extern char *var_int_filt_classes;
 
+ /*
+  * Mailbox ownership.
+  */
+#define VAR_STRICT_MBOX_OWNER	"strict_mailbox_ownership"
+#define DEF_STRICT_MBOX_OWNER	1
+extern bool var_strict_mbox_owner;
+
 /* LICENSE
 /* .ad
 /* .fi
diff --git a/src/global/mail_version.h b/src/global/mail_version.h
index ae94ab9..7ceadad 100644
--- a/src/global/mail_version.h
+++ b/src/global/mail_version.h
@@ -20,8 +20,8 @@
   * Patches change both the patchlevel and the release date. Snapshots have no
   * patchlevel; they change the release date only.
   */
-#define MAIL_RELEASE_DATE	"20080131"
-#define MAIL_VERSION_NUMBER	"2.4.7"
+#define MAIL_RELEASE_DATE	"20080726"
+#define MAIL_VERSION_NUMBER	"2.4.7-r1"
 
 #ifdef SNAPSHOT
 # define MAIL_VERSION_DATE	"-" MAIL_RELEASE_DATE
diff --git a/src/local/local.c b/src/local/local.c
index 557be6f..72ea49f 100644
--- a/src/local/local.c
+++ b/src/local/local.c
@@ -378,6 +378,10 @@
 /*	address (see prepend_delivered_header) only once, at the start of
 /*	a delivery attempt; do not update the Delivered-To: address while
 /*	expanding aliases or .forward files.
+/* .PP
+/*	Available in Postfix version 2.4.7-r1 and later:
+/* .IP "\fBstrict_mailbox_ownership (yes)\fR"
+/*	Defer delivery when a mailbox file is not owned by its recipient.
 /* DELIVERY METHOD CONTROLS
 /* .ad
 /* .fi
@@ -468,7 +472,7 @@
 /*	Restrict \fBlocal\fR(8) mail delivery to external files.
 /* .IP "\fBcommand_expansion_filter (see 'postconf -d' output)\fR"
 /*	Restrict the characters that the \fBlocal\fR(8) delivery agent allows in
-/*	$name expansions of $mailbox_command.
+/*	$name expansions of $mailbox_command and $command_execution_directory.
 /* .IP "\fBdefault_privs (nobody)\fR"
 /*	The default rights used by the \fBlocal\fR(8) delivery agent for delivery
 /*	to external file or command.
@@ -480,6 +484,10 @@
 /* .IP "\fBexecution_directory_expansion_filter (see 'postconf -d' output)\fR"
 /*	Restrict the characters that the \fBlocal\fR(8) delivery agent allows
 /*	in $name expansions of $command_execution_directory.
+/* .PP
+/*	Available in Postfix version 2.4.7-r1 and later:
+/* .IP "\fBstrict_mailbox_ownership (yes)\fR"
+/*	Defer delivery when a mailbox file is not owned by its recipient.
 /* MISCELLANEOUS CONTROLS
 /* .ad
 /* .fi
@@ -641,6 +649,7 @@ int     var_mailtool_compat;
 char   *var_mailbox_lock;
 int     var_mailbox_limit;
 bool    var_frozen_delivered;
+bool    var_strict_mbox_owner;
 
 int     local_cmd_deliver_mask;
 int     local_file_deliver_mask;
@@ -887,6 +896,7 @@ int     main(int argc, char **argv)
 	VAR_STAT_HOME_DIR, DEF_STAT_HOME_DIR, &var_stat_home_dir,
 	VAR_MAILTOOL_COMPAT, DEF_MAILTOOL_COMPAT, &var_mailtool_compat,
 	VAR_FROZEN_DELIVERED, DEF_FROZEN_DELIVERED, &var_frozen_delivered,
+	VAR_STRICT_MBOX_OWNER, DEF_STRICT_MBOX_OWNER, &var_strict_mbox_owner,
 	0,
     };
 
diff --git a/src/local/mailbox.c b/src/local/mailbox.c
index 92bd79d..d35ef66 100644
--- a/src/local/mailbox.c
+++ b/src/local/mailbox.c
@@ -194,6 +194,12 @@ static int deliver_mailbox_file(LOCAL_STATE state, USER_ATTR usr_attr)
 	    vstream_fclose(mp->fp);
 	    dsb_simple(why, "5.2.0",
 		       "destination %s is not a regular file", mailbox);
+	} else if (var_strict_mbox_owner && st.st_uid != usr_attr.uid) {
+	    vstream_fclose(mp->fp);
+	    dsb_simple(why, "4.2.0",
+		       "destination %s is not owned by recipient", mailbox);
+	    msg_warn("specify \"%s = no\" to ignore mailbox ownership mismatch",
+		     VAR_STRICT_MBOX_OWNER);
 	} else {
 	    end = vstream_fseek(mp->fp, (off_t) 0, SEEK_END);
 	    mail_copy_status = mail_copy(COPY_ATTR(state.msg_attr), mp->fp,
diff --git a/src/virtual/mailbox.c b/src/virtual/mailbox.c
index 09fc54b..f0ad6eb 100644
--- a/src/virtual/mailbox.c
+++ b/src/virtual/mailbox.c
@@ -125,6 +125,12 @@ static int deliver_mailbox_file(LOCAL_STATE state, USER_ATTR usr_attr)
 	    msg_warn("recipient %s: destination %s is not a regular file",
 		     state.msg_attr.rcpt.address, usr_attr.mailbox);
 	    dsb_simple(why, "5.3.5", "mail system configuration error");
+	} else if (var_strict_mbox_owner && st.st_uid != usr_attr.uid) {
+	    vstream_fclose(mp->fp);
+	    dsb_simple(why, "4.2.0",
+	      "destination %s is not owned by recipient", usr_attr.mailbox);
+	    msg_warn("specify \"%s = no\" to ignore mailbox ownership mismatch",
+		     VAR_STRICT_MBOX_OWNER);
 	} else {
 	    end = vstream_fseek(mp->fp, (off_t) 0, SEEK_END);
 	    mail_copy_status = mail_copy(COPY_ATTR(state.msg_attr), mp->fp,
diff --git a/src/virtual/virtual.c b/src/virtual/virtual.c
index 7d6e1b8..57b4098 100644
--- a/src/virtual/virtual.c
+++ b/src/virtual/virtual.c
@@ -183,6 +183,10 @@
 /* .IP "\fBvirtual_transport (virtual)\fR"
 /*	The default mail delivery transport and next-hop destination for
 /*	final delivery to domains listed with $virtual_mailbox_domains.
+/* .PP
+/*	Available in Postfix version 2.4.7-r1 and later:
+/* .IP "\fBstrict_mailbox_ownership (yes)\fR"
+/*	Defer delivery when a mailbox file is not owned by its recipient.
 /* LOCKING CONTROLS
 /* .ad
 /* .fi
@@ -329,6 +333,7 @@ char   *var_virt_mailbox_base;
 char   *var_virt_mailbox_lock;
 int     var_virt_mailbox_limit;
 char   *var_mail_spool_dir;		/* XXX dependency fix */
+bool    var_strict_mbox_owner;
 
  /*
   * Mappings.
@@ -504,6 +509,10 @@ int     main(int argc, char **argv)
 	VAR_VIRT_MAILBOX_LOCK, DEF_VIRT_MAILBOX_LOCK, &var_virt_mailbox_lock, 1, 0,
 	0,
     };
+    static const CONFIG_BOOL_TABLE bool_table[] = {
+	VAR_STRICT_MBOX_OWNER, DEF_STRICT_MBOX_OWNER, &var_strict_mbox_owner,
+	0,
+    };
 
     /*
      * Fingerprint executables and core dumps.
@@ -513,6 +522,7 @@ int     main(int argc, char **argv)
     single_server_main(argc, argv, local_service,
 		       MAIL_SERVER_INT_TABLE, int_table,
 		       MAIL_SERVER_STR_TABLE, str_table,
+		       MAIL_SERVER_BOOL_TABLE, bool_table,
 		       MAIL_SERVER_PRE_INIT, pre_init,
 		       MAIL_SERVER_POST_INIT, post_init,
 		       MAIL_SERVER_PRE_ACCEPT, pre_accept,