List administrivia: some emails are not getting through to subscribers

Greg Newby gbnewby at pglaf.org
Sat Dec 26 23:02:29 PST 2020


Hi, folks. Here is FYI concerning email delivery failures for cypherpunks:

Since the afternoon (PST) of December 23, an issue with the upstream network provider's DNS has evidently caused some list recipients to not get messages.

The issue is that the recipient's email provider rejects messages from lists.cpunks.org (a.k.a., pglaf.org) due to there being no PTR record in the DNS. PTR is also known as reverse DNS, and is one of the ways that network providers try to mitigate spam.

In fact there is a valid PTR. A command like "dig -x 65.50.255.19" shows this.

But some providers are getting NXDOMAIN when they look up the PTR, which means the query is rejected from the network provider that holds the IPv4 address space.

This issue is now escalated with our hosting provider, and they need to bring it to their network provider. I hope it will be addressed soon.

Meanwhile, some subscribers will not be getting messages. Or, perhaps, only getting some messages. The list archives, at https://lists.cpunks.org, are where you can find all the messages to the list.

This does not seem to impact incoming messages: any subscriber may post, as usual. But list messages going *to* subscribers might not be received (including this one).

Some messages might eventually be delivered if the issue is fixed soon, but many will bounce and will not be delivered. So far, mailman has not automatically unsubscribed anyone due to these delivery failures, and I've twiddled the server setting to try to prevent any auto-unsubscriptions.

Apologies for this problem. If you receive this message, and seem to be receiving all messages, then the issue is probably not impacting your email service provider.

If you didn't get this message but see it in the archive, I hope this explanation is helpful. I would be interested to hear from anyone who is getting some, but not all messages - that might help to narrow in on what part of the upstream network provider's systems are failing.

Best regards to all,
  Greg (your current cypherpunks list maintainer)


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