From fdcc82839543d636c1270ecf9fb166c347d01e21 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?C=C3=A9dric=20Krier?= <ced@b2ck.com>
Date: Sun, 26 Sep 2021 23:11:21 +0200
Subject: [PATCH] Add set_from_header in email tools

issue10753
review377121002
---
 CHANGELOG               |  1 +
 doc/ref/tools/email.rst | 10 ++++++++++
 doc/ref/tools/index.rst |  1 +
 trytond/ir/email_.py    | 11 +++--------
 trytond/res/user.py     |  3 ++-
 trytond/tools/email_.py | 23 +++++++++++++++++++++++
 6 files changed, 40 insertions(+), 9 deletions(-)
 create mode 100644 doc/ref/tools/email.rst
 create mode 100644 trytond/tools/email_.py

diff --git a/CHANGELOG b/CHANGELOG
index a10256266a..d982e7b5de 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,4 @@
+* Add set_from_header in email tools
 * Add grouping attribute to numeric widgets
 * Ensure with a test that objects in the Pool have __slots__
 * Use bigdecimal tag for XML-RPC
diff --git a/doc/ref/tools/email.rst b/doc/ref/tools/email.rst
new file mode 100644
index 0000000000..452d7d35d4
--- /dev/null
+++ b/doc/ref/tools/email.rst
@@ -0,0 +1,10 @@
+.. _ref-tools-email_:
+.. module:: trytond.tools.email_
+
+=====
+Email
+=====
+
+.. method:: set_from_header(message, sender, from\_)
+
+Fill email headers to appear at best from the address.
diff --git a/doc/ref/tools/index.rst b/doc/ref/tools/index.rst
index 80ce14bc16..d74ac88241 100644
--- a/doc/ref/tools/index.rst
+++ b/doc/ref/tools/index.rst
@@ -10,5 +10,6 @@ Tools API reference.
     :maxdepth: 1
 
     misc
+    email
     singleton
     immutabledict
diff --git a/trytond/ir/email_.py b/trytond/ir/email_.py
index b066895e6c..5e2f0f18e4 100644
--- a/trytond/ir/email_.py
+++ b/trytond/ir/email_.py
@@ -28,6 +28,7 @@ from trytond.rpc import RPC
 from trytond.sendmail import sendmail_transactional, SMTPDataManager
 from trytond.tools import escape_wildcard
 from trytond.tools.string_ import StringMatcher
+from trytond.tools.email_ import set_from_header
 from trytond.transaction import Transaction
 
 from .resource import ResourceAccessMixin
@@ -164,14 +165,8 @@ class Email(ResourceAccessMixin, ModelSQL, ModelView):
                 msg.attach(attachment)
         else:
             msg = content
-        msg['From'] = from_ = config.get('email', 'from')
-        if user.email:
-            if user.name:
-                user_email = formataddr((user.name, user.email))
-            else:
-                user_email = user.email
-            msg['Behalf-Of'] = user_email
-            msg['Reply-To'] = user_email
+        from_ = config.get('email', 'from')
+        set_from_header(msg, from_, user.email or from_)
         msg['To'] = ', '.join(formataddr(a) for a in getaddresses([to]))
         msg['Cc'] = ', '.join(formataddr(a) for a in getaddresses([cc]))
         msg['Subject'] = Header(subject, 'utf-8')
diff --git a/trytond/res/user.py b/trytond/res/user.py
index 01f68c1599..51bdcad48a 100644
--- a/trytond/res/user.py
+++ b/trytond/res/user.py
@@ -55,6 +55,7 @@ from trytond.report import Report, get_email
 from trytond.rpc import RPC
 from trytond.sendmail import sendmail_transactional
 from trytond.tools import grouped_slice
+from trytond.tools.email_ import set_from_header
 from trytond.transaction import Transaction
 from trytond.url import host, http_host
 from trytond.wizard import Wizard, StateView, Button, StateTransition
@@ -93,7 +94,7 @@ def _send_email(from_, users, email_func):
             logger.info("Missing address for '%s' to send email", user.login)
             continue
         msg, title = email_func(user)
-        msg['From'] = from_ or from_cfg
+        set_from_header(msg, from_cfg, from_ or from_cfg)
         msg['To'] = user.email
         msg['Subject'] = Header(title, 'utf-8')
         sendmail_transactional(from_cfg, [user.email], msg)
diff --git a/trytond/tools/email_.py b/trytond/tools/email_.py
new file mode 100644
index 0000000000..f8141ec84d
--- /dev/null
+++ b/trytond/tools/email_.py
@@ -0,0 +1,23 @@
+# This file is part of Tryton.  The COPYRIGHT file at the top level of
+# this repository contains the full copyright notices and license terms.
+from email.utils import parseaddr
+
+
+def _domainaddr(address):
+    _, email = parseaddr(address)
+    if '@' in email:
+        return email.split('@', 1)[1]
+
+
+def set_from_header(message, sender, from_):
+    "Fill email headers to appear at best from the address"
+    if parseaddr(sender)[1] != parseaddr(from_)[1]:
+        if _domainaddr(sender) == _domainaddr(from_):
+            message['From'] = from_
+            message['Sender'] = sender
+        else:
+            message['From'] = sender
+            message['On-Behalf-Of'] = from_
+            message['Reply-To'] = from_
+    else:
+        message['From'] = from_