bulkdeliver(): Rework the SMTP error handling to fix a problem

described here:

http://mail.python.org/pipermail/mailman-developers/2003-November/016119.html

The issue is that if we get an SMTPResponseException with a permanent
error code, we don't want to add all the recipients to the failures
dict, otherwise they'll all score a bounce.  That's not appropriate
because the message is being rejected by the local smtpd for reasons
having to do with the content of the message, not because there's some
delivery problem to the recipient.

Log all problems now to logs/smtp-failure.

1 files changed, 21 insertions, 10 deletions

diff --git a/Mailman/Handlers/SMTPDirect.py b/Mailman/Handlers/SMTPDirect.py
index acaa77e2..c61336fe 100644
--- a/Mailman/Handlers/SMTPDirect.py
+++ b/Mailman/Handlers/SMTPDirect.py
@@ -349,16 +349,27 @@ def bulkdeliver(mlist, msg, msgdata, envsender, failures, conn):
         # Send the message
         refused = conn.sendmail(envsender, recips, msgtext)
     except smtplib.SMTPRecipientsRefused, e:
+        syslog('smtp-failure', 'All recipients refused: %s', e)
         refused = e.recipients
-    # MTA not responding, or other socket problems, or any other kind of
-    # SMTPException.  In that case, nothing got delivered
-    except (socket.error, smtplib.SMTPException, IOError), e:
-        # BAW: should this be configurable?
-        syslog('smtp', 'All recipients refused: %s', e)
-        # If the exception had an associated error code, use it, otherwise,
-        # fake it with a non-triggering exception code
-        errcode = getattr(e, 'smtp_code', -1)
-        errmsg = getattr(e, 'smtp_error', 'ignore')
+    except smtplib.SMTPResponseException, e:
+        syslog('smtp-failure', 'SMTP session failure: %s, %s',
+               e.smtp_code, smtp_error)
+        # If this was a permanent failure, don't add the recipients to the
+        # refused, because we don't want them to be added to failures.
+        # Otherwise, if the MTA rejects the message because of the message
+        # content (e.g. it's spam, virii, or has syntactic problems), then
+        # this will end up registering a bounce score for every recipient.
+        # Definitely /not/ what we want.
+        if e.smtp_code < 500 or e.smtp_code == 552:
+            # It's a temporary failure
+            for r in recips:
+                refused[r] = (e.smtp_code, e.smtp_error)
+    except (socket.error, IOError, smtplib.SMTPException), e:
+        # MTA not responding, or other socket problems, or any other kind of
+        # SMTPException.  In that case, nothing got delivered, so treat this
+        # as a temporary failure.
+        syslog('smtp-failure', 'Low level smtp connection error: %s', e)
+        error = str(e)
         for r in recips:
-            refused[r] = (errcode, errmsg)
+            refused[r] = (-1, error)
     failures.update(refused)