3 files changed, 74 insertions, 18 deletions

diff --git a/src/mailman/mta/bulk.py b/src/mailman/mta/bulk.py
index 21bbd1713..be740c9cd 100644
--- a/src/mailman/mta/bulk.py
+++ b/src/mailman/mta/bulk.py
@@ -147,4 +147,10 @@ class BulkDelivery:
             except smtplib.SMTPRecipientsRefused as error:
                 log.error('%s recipients refused: %s', message_id, error)
                 refused = error.recipients
+            except smtplib.SMTPResponseException as error:
+                log.error('%s response exception: %s', message_id, error)
+                refused = dict(
+                    # recipient -> (code, error)
+                    (recipient, (error.smtp_code, error.smtp_error))
+                    for recipient in recipients)
         return refused
diff --git a/src/mailman/mta/docs/bulk.txt b/src/mailman/mta/docs/bulk.txt
index fabc265b6..bcce7e4c7 100644
--- a/src/mailman/mta/docs/bulk.txt
+++ b/src/mailman/mta/docs/bulk.txt
@@ -338,14 +338,14 @@ local mail server which manages queuing and final delivery.  However, even
 this local mail server can produce delivery failures visible to Mailman in
 certain situations.
 
-For example, something could be seriously wrong with the mail server and it
-could refuse delivery to all recipients.
+For example, there could be a problem delivering to any of the specified
+recipients.
 
     # Tell the mail server to fail on the next 3 RCPT TO commands, one for
     # each recipient in the following message.
-    >>> smtpd.err_queue.put('rcpt')
-    >>> smtpd.err_queue.put('rcpt')
-    >>> smtpd.err_queue.put('rcpt')
+    >>> smtpd.err_queue.put(('rcpt', 500))
+    >>> smtpd.err_queue.put(('rcpt', 500))
+    >>> smtpd.err_queue.put(('rcpt', 500))
 
     >>> recipients = set([
     ...     'aperson@example.org',
@@ -373,3 +373,27 @@ could refuse delivery to all recipients.
     >>> messages = list(smtpd.messages)
     >>> len(messages)
     0
+
+Or there could be some other problem causing an SMTP response failure.
+
+    # Tell the mail server to register a temporary failure on the next MAIL
+    # FROM command.
+    >>> smtpd.err_queue.put(('mail', 450))
+
+    >>> failures = bulk.deliver(mlist, msg, msgdata)
+    >>> for address in sorted(failures):
+    ...     print address, failures[address][0], failures[address][1]
+    aperson@example.org 450 Error: SMTPResponseException
+    bperson@example.org 450 Error: SMTPResponseException
+    cperson@example.org 450 Error: SMTPResponseException
+
+    # Tell the mail server to register a permanent failure on the next MAIL
+    # FROM command.
+    >>> smtpd.err_queue.put(('mail', 500))
+
+    >>> failures = bulk.deliver(mlist, msg, msgdata)
+    >>> for address in sorted(failures):
+    ...     print address, failures[address][0], failures[address][1]
+    aperson@example.org 500 Error: SMTPResponseException
+    bperson@example.org 500 Error: SMTPResponseException
+    cperson@example.org 500 Error: SMTPResponseException
diff --git a/src/mailman/testing/mta.py b/src/mailman/testing/mta.py
index 81852a24b..d16b9f955 100644
--- a/src/mailman/testing/mta.py
+++ b/src/mailman/testing/mta.py
@@ -66,13 +66,25 @@ class StatisticsChannel(Channel):
 
     def smtp_RCPT(self, arg):
         """For testing, sometimes cause a non-25x response."""
-        if self._server.next_error == 'rcpt':
+        code = self._server.next_error('rcpt')
+        if code is None:
+            # Everything's cool.
+            Channel.smtp_RCPT(self, arg)
+        else:
             # The test suite wants this to fail.  The message corresponds to
             # the exception we expect smtplib.SMTP to raise.
-            self.push(b'500 Error: SMTPRecipientsRefused')
-        else:
+            self.push(b'%d Error: SMTPRecipientsRefused' % code)
+
+    def smtp_MAIL(self, arg):
+        """For testing, sometimes cause a non-25x response."""
+        code = self._server.next_error('mail')
+        if code is None:
             # Everything's cool.
-            Channel.smtp_RCPT(self, arg)
+            Channel.smtp_MAIL(self, arg)
+        else:
+            # The test suite wants this to fail.  The message corresponds to
+            # the exception we expect smtplib.SMTP to raise.
+            self.push(b'%d Error: SMTPResponseException' % code)
 
 
 
@@ -95,18 +107,32 @@ class ConnectionCountingServer(QueueServer):
         # controller upon request.
         self._oob_queue = oob_queue
         self._err_queue = err_queue
+        self._last_error = None
 
-    @property
-    def next_error(self):
-        """Return the next error, or None if nothing's on the stack.
+    def next_error(self, command):
+        """Return the next error for the SMTP command, if there is one.
 
-        :return: The next SMTP command that should error.
-        :rtype: string (lower cased) or None
+        :param command: The SMTP command for which an error might be
+            expected.  If the next error matches the given command, the
+            expected error code is returned.
+        :type command: string, lower-cased
+        :return: An SMTP error code
+        :rtype: integer
         """
-        try:
-            return self._err_queue.get_nowait()
-        except Empty:
-            return None
+        # If the last error we pulled from the queue didn't match, then we're
+        # caching it, and it might match this expected error.  If there is no
+        # last error in the cache, get one from the queue now.
+        if self._last_error is None:
+            try:
+                self._last_error = self._err_queue.get_nowait()
+            except Empty:
+                # No error is expected
+                return None
+        if self._last_error[0] == command:
+            code = self._last_error[1]
+            self._last_error = None
+            return code
+        return None
 
     def handle_accept(self):
         """See `lazr.smtp.server.Server`."""