Hi,
First time posting to this list. I have an interesting situation that I don't see anyone mention in the list archives, so I'm hoping someone can help me out.
I maintain a server with a few domains. The server runs Plesk and Mailman. There are about 50 mailing lists with number of subscribers ranging from a couple people to a few hundred people. All work fine.
There is an additional list with around 2500 subscribers. Messages sent to this list are being received with nearly 500 identical "Received-SPF: pass" lines. Besides seeming odd, it's particularly problematic as some domains are bouncing the emails because the header is too large.
The SPF lines look like this
Received-SPF: pass (SERVER-HOSTNAME-HERE: localhost is always allowed.) client-ip=127.0.0.1; envelope-from=BOUNCE-LIST-ADDRESS-HERE; helo=SERVER-HOSTNAME-HERE;
Where SERVER-HOSTNAME-HERE is our hostname and BOUNCE-LIST-ADDRESS-HERE is the list's bounce address. For what it's worth the server hostname and the domain of the list do not match.
This issue seems to be tied to the number of subscribers. We made a new list with a few subscribers and messages looked fine. We added the 2500 subscribers to the list and we saw the plentiful Received-SPF: pass entries.
Any ideas??
Thank you,
Ian
On 12/15/2014 02:13 PM, Ian wrote:
There is an additional list with around 2500 subscribers. Messages sent to this list are being received with nearly 500 identical "Received-SPF: pass" lines. Besides seeming odd, it's particularly problematic as some domains are bouncing the emails because the header is too large.
The SPF lines look like this
Received-SPF: pass (SERVER-HOSTNAME-HERE: localhost is always allowed.) client-ip=127.0.0.1; envelope-from=BOUNCE-LIST-ADDRESS-HERE; helo=SERVER-HOSTNAME-HERE;
Where SERVER-HOSTNAME-HERE is our hostname and BOUNCE-LIST-ADDRESS-HERE is the list's bounce address. For what it's worth the server hostname and the domain of the list do not match.
This issue seems to be tied to the number of subscribers. We made a new list with a few subscribers and messages looked fine. We added the 2500 subscribers to the list and we saw the plentiful Received-SPF: pass entries.
Based on your observations, I think what is happening is you have more or less default Mailman settings, and your lists are sending to 'chunked' groups of up to 500 recipients per message. I.e. one SMTP MAIL FROM transaction with up to 500 RCPT TO recipients, and your outgoing MTA is adding a Received-SPF: header for each recipient.
This seems a bit strange for the MTA to do that, and may be a configuration issue with the MTA, but you can deal with it in Mailman. If I am correct on the cause, you could try putting
SMTP_MAX_RCPTS = n
in mm_cfg.py where n is a small number like 5 or 10 and restarting Mailman. The default for this setting is 500. It limits the number of recipients per SMTP transaction.
Also, you can try enabling VERP for better bounce recognition by putting
VERP_PASSWORD_REMINDERS = Yes VERP_PERSONALIZED_DELIVERIES = Yes VERP_DELIVERY_INTERVAL = 1
in mm_cfg.py and restarting Mailman. VERP_DELIVERY_INTERVAL = 1 will override SMTP_MAX_RCPTS, effectively setting it to 1. The VERP settings will cause messages to be sent with a VERP like envelope from listname-bounces+user=example.com@your_hostname where user@example.com is the recipient.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
participants (2)
-
Ian -
Mark Sapiro