Peter Knowles writes:
What is the best way to deal with feedback loop messages where the provider has redacted the email address of the party who filed the complaint?
What do you want to do with this information? Just unsubscribe that user? I'd say pass the buck back to the provider.
First, you need to be sure that you have not passed any spam, and second that your mailman host DKIM signs all its mail. You must have a subscribe and confirm-by-email process. If all that is true, then you can make a reasonable case that the user really just wants to unsubscribe, and did subscribe themselves in the first place. Write to the postmaster at the provider (or whoever the contact is), and send them your unsubscribe link, and tell them to pass it on to the user.
If they won't do that, write a "more in sorrow than in anger" message to the list explaining that Beavis and Butthead ISP is about to ban your list due to spurious complaints, that they won't help their users unsubscribe and conceal the information required for the list admin to do it, and so you are setting all of their users to nomail. Then do it. You're not hurting anybody, because if you don't do this, the ISP will ban you and they're effectively off the list anyway.
This isn't 100% effective, because it's quite possible that the subscribed address is in a different domain, and is just forwarding to B&B.net.
If you're actually sending commercial email (solicited, of course!) and that would hit your bottom line, I'm sorry, but you're screwed. You just keep going and hope they don't ban you.
Does Mailman have any built in methods on dealing with this issue?
No. This is a people problem, and the broken brains are not at your site. There's no automatic fix.
At the moment we "force" a custom footer on all messages which includes the recipients email address, and the list they belong to, but recently a few ISPs have even been redacting data in that part of the message.
Since you have full personalization set on, each recipient is getting a different message, and therefore each message goes in a separate SMTP transaction, and will have a separate Received line (for receipt *from* Mailman) and a separate MTA queue number. Your MTA log should be able to tell you where it went.
If they're redacting the trace headers, well, again, there's nothing you can do.
Regards,