fix is_automatic_out_of_office: only use "Auto-Submitted" header

app/email/headers.py

@@ -43,6 +43,7 @@ MIME_HEADERS = [
 # convert to lowercase to facilitate header look up
 MIME_HEADERS = [h.lower() for h in MIME_HEADERS]
 
-# if any of these headers are present, that means automatic out of office email
-AUTO_REPLY1 = "X-Autoreply"
-AUTO_REPLY2 = "Auto-Submitted"
+
+# according to https://datatracker.ietf.org/doc/html/rfc3834#section-3.1.7, this header should be set to  "auto-replied"
+# however on hotmail, this is set to "auto-generated"
+AUTO_SUBMITTED = "Auto-Submitted"

app/email/status.py

@@ -5,7 +5,7 @@ E202 = "250 Unsubscribe request accepted"
 E203 = "250 SL E203 email can't be sent from a reverse-alias"
 E204 = "250 SL E204 ignore"
 E205 = "250 SL E205 bounce handled"
-# out of office status
+# out-of-office status
 E206 = "250 SL E206 Out of office"
 
 # if mail_from is a IgnoreBounceSender, no need to send back a bounce report

app/models.py

@@ -1666,6 +1666,7 @@ class EmailLog(Base, ModelMixin):
     forward = orm.relationship(Contact)
 
     contact = orm.relationship(Contact, backref="email_logs")
+    alias = orm.relationship(Alias)
     mailbox = orm.relationship("Mailbox", lazy="joined", foreign_keys=[mailbox_id])
     user = orm.relationship(User)
 

email_handler.py

@@ -1752,15 +1752,19 @@ def handle_spam(
 
 
 def is_automatic_out_of_office(msg: Message) -> bool:
-    if msg[headers.AUTO_REPLY1] is not None:
-        LOG.d(
-            "out-of-office email %s:%s", headers.AUTO_REPLY1, msg[headers.AUTO_REPLY1]
-        )
-        return True
+    """
+    Return whether an email is out-of-office
+    For info, out-of-office is sent to the envelope mail_from and not the From: header
+    More info on https://datatracker.ietf.org/doc/html/rfc3834#section-4 and https://support.google.com/mail/thread/21246740/my-auto-reply-filter-isn-t-replying-to-original-sender-address?hl=en&msgid=21261237
+    """
+    if msg[headers.AUTO_SUBMITTED] is None:
+        return False
 
-    if msg[headers.AUTO_REPLY2] is not None:
+    if msg[headers.AUTO_SUBMITTED].lower() in ("auto-replied", "auto-generated"):
         LOG.d(
-            "out-of-office email %s:%s", headers.AUTO_REPLY2, msg[headers.AUTO_REPLY2]
+            "out-of-office email %s:%s",
+            headers.AUTO_SUBMITTED,
+            msg[headers.AUTO_SUBMITTED],
         )
         return True
 

tests/test_email_handler.py

@@ -53,11 +53,11 @@ def test_is_automatic_out_of_office():
     msg = EmailMessage()
     assert not is_automatic_out_of_office(msg)
 
-    msg[headers.AUTO_REPLY1] = "yes"
+    msg[headers.AUTO_SUBMITTED] = "auto-replied"
     assert is_automatic_out_of_office(msg)
 
-    del msg[headers.AUTO_REPLY1]
+    del msg[headers.AUTO_SUBMITTED]
     assert not is_automatic_out_of_office(msg)
 
-    msg[headers.AUTO_REPLY2] = "auto-replied"
+    msg[headers.AUTO_SUBMITTED] = "auto-generated"
     assert is_automatic_out_of_office(msg)