Adding upstream version 3.5.24.upstream/3.5.24upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 113 insertions, 0 deletions

diff --git a/src/global/smtputf8.h b/src/global/smtputf8.h
new file mode 100644
index 0000000..95d6583
--- /dev/null
+++ b/src/global/smtputf8.h
@@ -0,0 +1,113 @@
+#ifndef _SMTPUTF8_H_INCLUDED_
+#define _SMTPUTF8_H_INCLUDED_
+
+/*++
+/* NAME
+/*	smtputf8 3h
+/* SUMMARY
+/*	SMTPUTF8 support
+/* SYNOPSIS
+/*	#include <smtputf8.h>
+/* DESCRIPTION
+/* .nf
+
+ /*
+  * Avoiding chicken-and-egg problems during the initial SMTPUTF8 roll-out in
+  * environments with pre-existing mail flows that contain UTF8.
+  * 
+  * Prior to SMTPUTF8, mail flows that contain UTF8 worked because the vast
+  * majority of MTAs is perfectly capable of handling UTF8 in address
+  * localparts (and in headers), even if pre-SMTPUTF8 standards do not
+  * support this practice.
+  * 
+  * When turning on Postfix SMTPUTF8 support for the first time, we don't want
+  * to suddenly break pre-existing mail flows that contain UTF8 because 1) a
+  * client does not request SMTPUTF8 support, and because 2) a down-stream
+  * MTA does not announce SMTPUTF8 support.
+  * 
+  * While 1) is easy enough to avoid (keep accepting UTF8 in address localparts
+  * just like Postfix has always done), 2) presents a thornier problem. The
+  * root cause of that problem is the need for SMTPUTF8 autodetection.
+  * 
+  * What is SMTPUTF8 autodetection? Postfix cannot rely solely on the sender's
+  * declaration that a message requires SMTPUTF8 support, because UTF8 may be
+  * introduced during local processing (for example, the client hostname in
+  * Postfix's Received: header, adding @$myorigin or .$mydomain to an
+  * incomplete address, address rewriting, alias expansion, automatic BCC
+  * recipients, local forwarding, and changes made by header checks or Milter
+  * applications).
+  * 
+  * In summary, after local processing has happened, Postfix may decide that a
+  * message requires SMTPUTF8 support, even when that message initially did
+  * not require SMTPUTF8 support. This could make the message undeliverable
+  * to destinations that do not support SMTPUTF8. In an environment with
+  * pre-existing mail flows that contain UTF8, we want to avoid disrupting
+  * those mail flows when rolling out SMTPUTF8 support.
+  * 
+  * For the vast majority of sites, the simplest solution is to autodetect
+  * SMTPUTF8 support only for Postfix sendmail command-line submissions, at
+  * least as long as SMTPUTF8 support has not yet achieved wold domination.
+  * 
+  * However, sites that add UTF8 content via local processing (see above) should
+  * autodetect SMTPUTF8 support for all email.
+  * 
+  * smtputf8_autodetect() uses the setting of the smtputf8_autodetect_classes
+  * parameter, and the mail source classes defined in mail_params.h.
+  */
+extern int smtputf8_autodetect(int);
+
+ /*
+  * The flag SMTPUTF8_FLAG_REQUESTED is raised on request by the sender, or
+  * when a queue file contains at least one UTF8 envelope recipient. One this
+  * flag is raised it is preserved when mail is forwarded or bounced.
+  * 
+  * The flag SMTPUTF8_FLAG_HEADER is raised when a queue file contains at least
+  * one UTF8 message header.
+  * 
+  * The flag SMTPUTF8_FLAG_SENDER is raised when a queue file contains an UTF8
+  * envelope sender.
+  * 
+  * The three flags SMTPUTF8_FLAG_REQUESTED/HEADER/SENDER are stored in the
+  * queue file, are sent with delivery requests to Postfix delivery agents,
+  * and are sent with "flush" requests to the bounce daemon to ensure that
+  * the resulting notification message will have a content-transfer-encoding
+  * of 8bit.
+  * 
+  * In the future, mailing lists will have a mix of UTF8 and non-UTF8
+  * subscribers. With the following flag, Postfix can avoid requiring
+  * SMTPUTF8 delivery when it isn't really needed.
+  * 
+  * The flag SMTPUTF8_FLAG_RECIPIENT is raised when a delivery request (NOT:
+  * message) contains at least one UTF8 envelope recipient. The flag is NOT
+  * stored in the queue file. The flag sent in requests to the bounce daemon
+  * ONLY when bouncing a single recipient. The flag is used ONLY in requests
+  * to Postfix delivery agents, to give Postfix flexibility when delivering
+  * messages to non-SMTPUTF8 servers.
+  * 
+  * If a delivery request has none of the flags SMTPUTF8_FLAG_RECIPIENT,
+  * SMTPUTF8_FLAG_SENDER, or SMTPUTF8_FLAG_HEADER, then the message can
+  * safely be delivered to a non-SMTPUTF8 server (DSN original recipients
+  * will be encoded appropriately per RFC 6533).
+  * 
+  * To allow even more SMTPUTF8 mail to be sent to non-SMTPUTF8 servers,
+  * implement RFC 2047 header encoding in the Postfix SMTP client, and update
+  * the SMTP client protocol engine.
+  */
+#define SMTPUTF8_FLAG_NONE	(0)
+#define SMTPUTF8_FLAG_REQUESTED	(1<<0)	/* queue file/delivery/bounce request */
+#define SMTPUTF8_FLAG_HEADER	(1<<1)	/* queue file/delivery/bounce request */
+#define SMTPUTF8_FLAG_SENDER	(1<<2)	/* queue file/delivery/bounce request */
+#define SMTPUTF8_FLAG_RECIPIENT	(1<<3)	/* delivery request only */
+
+/* LICENSE
+/* .ad
+/* .fi
+/*	The Secure Mailer license must be distributed with this software.
+/* AUTHOR(S)
+/*	Wietse Venema
+/*	IBM T.J. Watson Research
+/*	P.O. Box 704
+/*	Yorktown Heights, NY 10598, USA
+/*--*/
+
+#endif