[tor-commits] [gettor/master] Ignore emails from Mail Delivery System

[cohosh at torproject.org]

commit b78bc3ff922ea53d972f994e670dd3c39f97e5d0
Author: Cecylia Bocovich <cohosh at torproject.org>
Date:   Fri May 22 16:36:36 2020 -0400

    Ignore emails from Mail Delivery System
    
    This ignores emails with the username "MAILER-DAEMON", a common email
    for mail delivery systems. The goal of this is to avoid getting into a
    loop with mail delivery system autoresponders after a bounced email.
---
 gettor/parse/email.py       | 8 +++++++-
 tests/test_email_service.py | 7 +++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/gettor/parse/email.py b/gettor/parse/email.py
index 5a3e45e..d37614d 100644
--- a/gettor/parse/email.py
+++ b/gettor/parse/email.py
@@ -84,6 +84,11 @@ class EmailParser(object):
                 "Email address normalized and validated.",
                 system="email parser"
             )
+
+            # Add a check for auto-generated mail-daemon emails
+            if "mailer-daemon@" in norm_addr.lower():
+                raise AddressError("Received mail from Mail Delivery System {}"
+                        .format(msg['From']))
             return True
 
         else:
@@ -206,7 +211,8 @@ class EmailParser(object):
         try:
             self.validate(norm_addr, msg)
         except AddressError as e:
-            log.message("Address error: {}".format(e.args))
+            log.msg("Address error: {}".format(e.args))
+            return {}
 
         hid = hashlib.sha256(norm_addr.encode('utf-8'))
         log.msg(
diff --git a/tests/test_email_service.py b/tests/test_email_service.py
index 3803e79..a41669f 100644
--- a/tests/test_email_service.py
+++ b/tests/test_email_service.py
@@ -289,6 +289,13 @@ class EmailServiceTests(unittest.TestCase):
                 ">\n")
         self.assertEqual(request["command"], "help")
 
+    def test_bounce(self):
+        ep = conftests.EmailParser(self.settings, "gettor at torproject.org")
+        request = ep.parse("From: MAILER-DAEMON at mx1.riseup.net\n"
+                "Subject: Undelivered Mail Returned to Sender\r\n"
+                "To: gettor at torproject.org\n osx en\n")
+
+        self.assertEqual(request, {})
 
 if __name__ == "__main__":
     unittest.main()