Mailing List Issues

[Jeremy Newman]

We have been having issues with bounces and people getting removed from 
the list subscriptions as of late. It seems to mostly affect Gmail 
users, but some others have been getting kicked as well. Gmail is 
getting particularly picky about valid mail headers.

I'm looking into ways of preventing this from happening. I've done the 
following to prevent further issues:

  * Raise the bounce threshold in mailman to 10.0
  * Add SPF record to DNS
  * Add DMARC policy to DNS
  * Add DKIM key signing to all outbound mail, and matching key in DNS

We also have been hitting our bandwidth threshold at our co-lo. When 
this happens they start to drop packets on us as a form of throttling. 
This always happens when I do a full CDN flush. As this really chews up 
the bits when the mirrors re-sync.

To prevent that, we now have a background process watching for changed 
files on our master, and only changes will be flushed.

If you notice any further issues, or have suggestions, let me know.

Thanks.

-N