use getaddresses to parse multiple address from To, CC header. Remove get_addrs_from_header()

app/email_utils.py

@@ -538,24 +538,6 @@ def get_orig_message_from_spamassassin_report(msg: Message) -> Message:
             return part
 
 
-def get_addrs_from_header(msg: Message, header) -> [str]:
-    """Get all addresses contained in `header`
-    Used for To or CC header.
-    """
-    ret = []
-    header_content = msg.get_all(header)
-    if not header_content:
-        return ret
-
-    for addrs in header_content:
-        addrs = get_header_unicode(addrs)
-        for addr in addrs.split(","):
-            ret.append(addr.strip())
-
-    # do not return empty string
-    return [r for r in ret if r]
-
-
 def get_spam_info(msg: Message, max_score=None) -> (bool, str):
     """parse SpamAssassin header to detect whether a message is classified as spam.
       Return (is spam, spam status detail)

email_handler.py

@@ -41,7 +41,7 @@ from email.encoders import encode_noop
 from email.message import Message
 from email.mime.application import MIMEApplication
 from email.mime.multipart import MIMEMultipart
-from email.utils import formataddr, make_msgid, formatdate
+from email.utils import formataddr, make_msgid, formatdate, getaddresses
 from io import BytesIO
 from smtplib import SMTP, SMTPRecipientsRefused
 from typing import List, Tuple, Optional
@@ -88,7 +88,6 @@ from app.email_utils import (
     render,
     get_orig_message_from_bounce,
     delete_all_headers_except,
-    get_addrs_from_header,
     get_spam_info,
     get_orig_message_from_spamassassin_report,
     parseaddr_unicode,
@@ -242,16 +241,12 @@ def replace_header_when_forward(msg: Message, alias: Alias, header: str):
     """
     Replace CC or To header by Reply emails in forward phase
     """
-    addrs = get_addrs_from_header(msg, header)
-
-    # Nothing to do
-    if not addrs:
-        return
-
     new_addrs: [str] = []
 
-    for addr in addrs:
-        contact_name, contact_email = parseaddr_unicode(addr)
+    for contact_name, contact_email in getaddresses(msg.get_all(header, [])):
+        # convert back to original then parse again to make sure contact_name is unicode
+        addr = formataddr((contact_name, contact_email))
+        contact_name, contact = parseaddr_unicode(addr)
 
         # no transformation when alias is already in the header
         if contact_email == alias.email:
@@ -309,17 +304,9 @@ def replace_header_when_reply(msg: Message, alias: Alias, header: str):
     """
     Replace CC or To Reply emails by original emails
     """
-    addrs = get_addrs_from_header(msg, header)
-
-    # Nothing to do
-    if not addrs:
-        return
-
     new_addrs: [str] = []
 
-    for addr in addrs:
-        _, reply_email = parseaddr_unicode(addr)
-
+    for _, reply_email in getaddresses(msg.get_all(header, [])):
         # no transformation when alias is already in the header
         if reply_email == alias.email:
             continue
@@ -330,7 +317,7 @@ def replace_header_when_reply(msg: Message, alias: Alias, header: str):
                 "%s email in reply phase %s must be reply emails", header, reply_email
             )
             # still keep this email in header
-            new_addrs.append(addr)
+            new_addrs.append(reply_email)
         else:
             new_addrs.append(formataddr((contact.name, contact.website_email)))
 

tests/test_email_utils.py

@@ -17,7 +17,6 @@ from app.email_utils import (
     add_header,
     to_bytes,
     generate_reply_email,
-    get_addrs_from_header,
 )
 from app.extensions import db
 from app.models import User, CustomDomain
@@ -409,22 +408,3 @@ def test_generate_reply_email(flask_client):
     # make sure reply_email only contain lowercase
     reply_email = generate_reply_email("TEST@example.org")
     assert reply_email.startswith("ra+test.at.example.org")
-
-
-def test_get_addrs_from_header():
-    msg = email.message_from_string("""To: abcd@test.org""")
-    assert get_addrs_from_header(msg, "To") == ["abcd@test.org"]
-
-    msg = email.message_from_string("""To: abcd@test.org, xyz@test.org""")
-    assert get_addrs_from_header(msg, "To") == ["abcd@test.org", "xyz@test.org"]
-
-    msg = email.message_from_string("""To: ABCD <abcd@test.org>, XYZ <xyz@test.org>""")
-    assert get_addrs_from_header(msg, "To") == [
-        "ABCD <abcd@test.org>",
-        "XYZ <xyz@test.org>",
-    ]
-
-    msg = email.message_from_string(
-        """To: =?unknown-8bit?q?test=40example=2eorg=2c_xyz=40test=2eorg?="""
-    )
-    assert get_addrs_from_header(msg, "To") == ["test@example.org", "xyz@test.org"]