bcrl on Don't Use a gmail.com Address

Comment on Don't Use a gmail.com Address

I think the difference between Google's DMARC policy for gmail.com and google.com says it all:

  bcrl@home:~/electronics/vrm/lm5017/test-lm5017-isobuck$ host -t txt _dmarc.gmail.com
  _dmarc.gmail.com descriptive text "v=DMARC1; p=none; sp=quarantine; rua=mailto:mailauth-reports@google.com"

  bcrl@home:~/electronics/vrm/lm5017/test-lm5017-isobuck$ host -t txt _dmarc.google.com
  _dmarc.google.com descriptive text "v=DMARC1; p=reject; rua=mailto:mailauth-reports@google.com"

rpdillon 5d

Wait, wouldn't setting gmail.com to p=reject break anyone using legacy email-forwarding setups and mailing lists?

bcrl 4d

No. DKIM signatures were designed to work when emails are forwarded. I run a couple of Linux related mailing lists, and the DKIM signature continues to validate specified headers and the body of the email when forwarded or resent via mailing lists. Dealing with that quirk happened a decade ago, and it is why most mailing lists no longer add headers or footers to emails with instructions on how to unsubscribe.

rpdillon 4d

Nice, thanks for the explanation. I haven't run a mailing list in over ten years, so I'm afraid I'm a bit out of date on the setup.

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