Add parseaddr_unicode()

app/email_utils.py

@@ -1,4 +1,5 @@
 import os
+from email.header import decode_header
 from email.message import Message
 from email.mime.base import MIMEBase
 from email.mime.multipart import MIMEMultipart
@@ -432,3 +433,18 @@ def get_spam_info(msg: Message) -> (bool, str):
     spamassassin_answer = spamassassin_status[: spamassassin_status.find(",")]
 
     return spamassassin_answer.lower() == "yes", spamassassin_status
+
+
+def parseaddr_unicode(addr) -> (str, str):
+    """Like parseaddr but return name in unicode instead of in RFC 2047 format
+    '=?UTF-8?B?TmjGoW4gTmd1eeG7hW4=?= <abcd@gmail.com>' -> ('Nhơn Nguyễn', "abcd@gmail.com")
+    """
+    name, email = parseaddr(addr)
+    email = email.lower()
+    if name:
+        decoded_string, charset = decode_header(name)[0]
+        if charset is not None:
+            return decoded_string.decode(charset), email
+        else:
+            return decoded_string, email
+

tests/test_email_utils.py

@@ -6,7 +6,7 @@ from app.email_utils import (
     can_be_used_as_personal_email,
     delete_header,
     add_or_replace_header,
-)
+    parseaddr_unicode)
 from app.extensions import db
 from app.models import User, CustomDomain
 
@@ -61,3 +61,17 @@ def test_add_or_replace_header():
 
     add_or_replace_header(msg, "H", "new")
     assert msg._headers == [("H", "new")]
+
+
+def test_parseaddr_unicode():
+    # ascii address
+    assert parseaddr_unicode("First Last <abcd@gmail.com>") == ("First Last", "abcd@gmail.com")
+
+    # Handle quote
+    assert parseaddr_unicode('"First Last" <abcd@gmail.com>') == ("First Last", "abcd@gmail.com")
+
+    # UTF-8 charset
+    assert parseaddr_unicode("=?UTF-8?B?TmjGoW4gTmd1eeG7hW4=?= <abcd@gmail.com>") == ('Nhơn Nguyễn', "abcd@gmail.com")
+
+    # iso-8859-1 charset
+    assert parseaddr_unicode("=?iso-8859-1?q?p=F6stal?= <abcd@gmail.com>") == ('pöstal', "abcd@gmail.com")