Re: [boost] Mangled "From" field in mailing list posts

On 13/06/2017 14:59, Olaf van der Spek via Boost wrote:

On Tue, Jun 13, 2017 at 10:22 AM, Vladimir Prus via Boost wrote:

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thanks for the explanation. So, if I understand correctly, the problem is that some *senders* have their domains configured to ask recipients to reject emails that don't pass DKIM or SPF? In other words, the question is not how many organizations have DMARC for inbound authentication, but how many users are sending emails to a mailing list (which, by definition, forwards email with modifications) while also requesting than any forwared with modifications emails are rejected by recipients? How many such sending users/domains do we have?

I personally think it would be reasonable to just require that posters don't use such domain configuration.

Doesn't gmail also use dmarc?

It does, as can be seen at https://dmarcian.com/dmarc-inspector/gmail.com But that configuration (p=none) asks recipient servers to report back to gmail about any problems they see, not drop email, whereas some other email providers have "p=reject".

...

If that's not possible, can't we make Mailman not add any footers, and don't add any DKIM signature of its own. Maybe, that will cause original DKIM signature to remain valid and DMARC check to pass?

The original From header is still problematic AFAIK.

It is my understanding that if you don't modify From header and don't modify body, then DKIM will pass and SPF will fail, and it's enough for one of the tests to pass. - Volodya