Use default email policy to parse raw email

The default policy uses the EmailMessage class instead of the Message class
from the compat32 policy.
The EmailMessage decodes automatically the header values.

Closes #13607

modules/inbound_email/inbound_email.py

@@ -7,7 +7,8 @@ import json
 import re
 import urllib
 import uuid
-from email.utils import getaddresses, parseaddr
+from email.policy import default as email_policy_default
+from email.utils import getaddresses
 from functools import partial
 
 from trytond.config import config
@@ -183,17 +184,19 @@ class Email(ModelSQL, ModelView):
     def _as_dict(self, raw):
         value = {}
         if isinstance(raw, str):
-            message = email.message_from_string(raw)
+            message = email.message_from_string(
+                raw, policy=email_policy_default)
         else:
-            message = email.message_from_bytes(raw)
+            message = email.message_from_bytes(
+                raw, policy=email_policy_default)
         if 'From' in message:
-            value['from'] = parseaddr(message.get('From'))[1]
+            value['from'] = getaddresses([message.get('From')])[0][1]
         for key in ['To', 'Cc', 'Bcc']:
             if key in message:
                 value[key.lower()] = [
                     a for _, a in getaddresses(message.get_all(key))]
         if 'Subject' in message:
-            value['subject'] = message.get('Subject')
+            value['subject'] = message['Subject']
         text = _email_text(message)
         if text is not None:
             value['text'] = text