diff --git a/tryton/modules/account_dunning_email/account.py b/modules/account_dunning_email/account.py
index 8513c27751c0e841f630bc6f4e511c0d8ee68ff0_bW9kdWxlcy9hY2NvdW50X2R1bm5pbmdfZW1haWwvYWNjb3VudC5weQ==..c7b9a8fd886428d866f215591c176269cab6a5c6_bW9kdWxlcy9hY2NvdW50X2R1bm5pbmdfZW1haWwvYWNjb3VudC5weQ== 100644
--- a/tryton/modules/account_dunning_email/account.py
+++ b/tryton/modules/account_dunning_email/account.py
@@ -9,8 +9,8 @@
 from trytond.pyson import Bool, Eval
 from trytond.report import get_email
 from trytond.sendmail import SMTPDataManager, sendmail_transactional
-from trytond.tools.email_ import set_from_header
+from trytond.tools.email_ import convert_ascii_email, set_from_header
 from trytond.transaction import Transaction
 from trytond.wizard import StateTransition
 
 
@@ -13,7 +13,14 @@
 from trytond.transaction import Transaction
 from trytond.wizard import StateTransition
 
 
+def _formataddr(pair):
+    name, address = pair
+    if name:
+        name = str(Header(name, 'utf-8'))
+    return formataddr((name, convert_ascii_email(address)))
+
+
 class Configuration(metaclass=PoolMeta):
     __name__ = 'account.configuration'
 
@@ -117,8 +124,8 @@
         contact = self.party.contact_mechanism_get(
             'email', usage=self.level.email_contact_mechanism)
         if contact and contact.email:
-            name = str(Header(contact.name or self.party.rec_name))
-            to.append(formataddr((name, contact.email)))
+            name = contact.name or self.party.rec_name
+            to.append(_formataddr((name, contact.email)))
         elif account_config.dunning_email_fallback:
             user = account_config.get_multivalue(
                 'dunning_email_fallback', company=self.company.id)
@@ -122,7 +129,7 @@
         elif account_config.dunning_email_fallback:
             user = account_config.get_multivalue(
                 'dunning_email_fallback', company=self.company.id)
-            to.append(formataddr((self.party.rec_name, user.email)))
+            to.append(_formataddr((self.party.rec_name, user.email)))
         cc = []
         bcc = []
         languages = set()
diff --git a/tryton/modules/marketing_automation/marketing_automation.py b/modules/marketing_automation/marketing_automation.py
index 8513c27751c0e841f630bc6f4e511c0d8ee68ff0_bW9kdWxlcy9tYXJrZXRpbmdfYXV0b21hdGlvbi9tYXJrZXRpbmdfYXV0b21hdGlvbi5weQ==..c7b9a8fd886428d866f215591c176269cab6a5c6_bW9kdWxlcy9tYXJrZXRpbmdfYXV0b21hdGlvbi9tYXJrZXRpbmdfYXV0b21hdGlvbi5weQ== 100644
--- a/tryton/modules/marketing_automation/marketing_automation.py
+++ b/tryton/modules/marketing_automation/marketing_automation.py
@@ -32,7 +32,7 @@
 from trytond.report import Report
 from trytond.sendmail import SMTPDataManager, sendmail_transactional
 from trytond.tools import grouped_slice, reduce_ids
-from trytond.tools.email_ import set_from_header
+from trytond.tools.email_ import convert_ascii_email, set_from_header
 from trytond.transaction import Transaction
 from trytond.url import http_host
 from trytond.wsgi import Base64Converter
@@ -55,7 +55,7 @@
 def _formataddr(name, email):
     if name:
         name = str(Header(name, 'utf-8'))
-    return formataddr((name, email))
+    return formataddr((name, convert_ascii_email(email)))
 
 
 class Scenario(Workflow, ModelSQL, ModelView):
diff --git a/tryton/modules/marketing_email/marketing.py b/modules/marketing_email/marketing.py
index 8513c27751c0e841f630bc6f4e511c0d8ee68ff0_bW9kdWxlcy9tYXJrZXRpbmdfZW1haWwvbWFya2V0aW5nLnB5..c7b9a8fd886428d866f215591c176269cab6a5c6_bW9kdWxlcy9tYXJrZXRpbmdfZW1haWwvbWFya2V0aW5nLnB5 100644
--- a/tryton/modules/marketing_email/marketing.py
+++ b/tryton/modules/marketing_email/marketing.py
@@ -31,7 +31,7 @@
 from trytond.report import Report, get_email
 from trytond.sendmail import SMTPDataManager, sendmail_transactional
 from trytond.tools import grouped_slice, reduce_ids
-from trytond.tools.email_ import set_from_header
+from trytond.tools.email_ import convert_ascii_email, set_from_header
 from trytond.transaction import Transaction, inactive_records
 from trytond.url import http_host
 from trytond.wizard import Button, StateTransition, StateView, Wizard
@@ -51,7 +51,7 @@
 def _formataddr(name, email):
     if name:
         name = str(Header(name, 'utf-8'))
-    return formataddr((name, email))
+    return formataddr((name, convert_ascii_email(email)))
 
 
 def _add_params(url, **params):
@@ -297,7 +297,8 @@
             set_from_header(msg, from_cfg, from_ or from_cfg)
             msg['To'] = record.email
             msg['Subject'] = Header(title, 'utf-8')
-            sendmail_transactional(from_cfg, [record.email], msg)
+            sendmail_transactional(
+                from_cfg, [convert_ascii_email(record.email)], msg)
 
     def request_unsubscribe(self, email, from_=None):
         pool = Pool()
@@ -322,7 +323,8 @@
                 set_from_header(msg, from_cfg, from_ or from_cfg)
                 msg['To'] = record.email
                 msg['Subject'] = Header(title, 'utf-8')
-                sendmail_transactional(from_cfg, [record.email], msg)
+                sendmail_transactional(
+                    from_cfg, [convert_ascii_email(record.email)], msg)
 
 
 class Message(Workflow, ModelSQL, ModelView):
diff --git a/tryton/modules/notification_email/notification.py b/modules/notification_email/notification.py
index 8513c27751c0e841f630bc6f4e511c0d8ee68ff0_bW9kdWxlcy9ub3RpZmljYXRpb25fZW1haWwvbm90aWZpY2F0aW9uLnB5..c7b9a8fd886428d866f215591c176269cab6a5c6_bW9kdWxlcy9ub3RpZmljYXRpb25fZW1haWwvbm90aWZpY2F0aW9uLnB5 100644
--- a/tryton/modules/notification_email/notification.py
+++ b/tryton/modules/notification_email/notification.py
@@ -6,7 +6,7 @@
 from email.mime.application import MIMEApplication
 from email.mime.multipart import MIMEMultipart
 from email.mime.nonmultipart import MIMENonMultipart
-from email.utils import formataddr, getaddresses, parseaddr
+from email.utils import formataddr, getaddresses
 
 from genshi.template import TextTemplate
 
@@ -17,7 +17,7 @@
 from trytond.pyson import Eval, TimeDelta
 from trytond.report import get_email
 from trytond.sendmail import SMTPDataManager, sendmail_transactional
-from trytond.tools.email_ import set_from_header
+from trytond.tools.email_ import convert_ascii_email, set_from_header
 from trytond.transaction import Transaction
 
 from .exceptions import TemplateError
@@ -195,8 +195,12 @@
             msg = content
 
         set_from_header(msg, sender, from_)
-        msg['To'] = ', '.join(formataddr(parseaddr(a)) for a in to)
-        msg['Cc'] = ', '.join(formataddr(parseaddr(a)) for a in cc)
+        msg['To'] = ', '.join(
+            formataddr((n, convert_ascii_email(a)))
+            for n, a in getaddresses(to))
+        msg['Cc'] = ', '.join(
+            formataddr((n, convert_ascii_email(a)))
+            for n, a in getaddresses(cc))
         msg['Subject'] = Header(title, 'utf-8')
         msg['Auto-Submitted'] = 'auto-generated'
         return msg, title
@@ -238,7 +242,8 @@
             cc, cc_languages = self._get_cc(record)
             bcc, bcc_languages = self._get_bcc(record)
             languages = to_languages | cc_languages | bcc_languages
-            to_addrs = [e for _, e in getaddresses(to + cc + bcc)]
+            to_addrs = [
+                convert_ascii_email(e) for _, e in getaddresses(to + cc + bcc)]
             if to_addrs:
                 msg, title = self.get_email(
                     record, from_, to, cc, bcc, languages)
diff --git a/tryton/trytond/trytond/ir/email_.py b/trytond/trytond/ir/email_.py
index 8513c27751c0e841f630bc6f4e511c0d8ee68ff0_dHJ5dG9uZC90cnl0b25kL2lyL2VtYWlsXy5weQ==..c7b9a8fd886428d866f215591c176269cab6a5c6_dHJ5dG9uZC90cnl0b25kL2lyL2VtYWlsXy5weQ== 100644
--- a/tryton/trytond/trytond/ir/email_.py
+++ b/tryton/trytond/trytond/ir/email_.py
@@ -27,7 +27,7 @@
 from trytond.rpc import RPC
 from trytond.sendmail import sendmail_transactional
 from trytond.tools import escape_wildcard
-from trytond.tools.email_ import set_from_header
+from trytond.tools.email_ import convert_ascii_email, set_from_header
 from trytond.tools.string_ import StringMatcher
 from trytond.transaction import Transaction
 
@@ -56,7 +56,7 @@
 def _formataddr(pair):
     "Format address without encoding"
     name, address = pair
-    address.encode('ascii')
+    convert_ascii_email(address).encode('ascii')
     if name:
         quotes = ''
         if specialsre.search(name):
@@ -167,8 +167,12 @@
             msg = content
         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['To'] = ', '.join(
+            formataddr((n, convert_ascii_email(a)))
+            for n, a in getaddresses([to]))
+        msg['Cc'] = ', '.join(
+            formataddr((n, convert_ascii_email(a)))
+            for n, a in getaddresses([cc]))
         msg['Subject'] = Header(subject, 'utf-8')
 
         to_addrs = list(filter(None, map(