I have a Mailman 3 server set up with OpenDKIM and Postfix. Each of the lists has been configured so that the DMARC mitigation is "Replace From: with list address" and DMARC Mitigate unconditionally is selected.

Everything seems to be working fine *except* when the system sends a notification email to the list owners of someone subscribing or unsubscribing. *Those* emails do not have the DKIM header added and are getting trapped by anti-spam systems as a result.

Any suggestions as to why this might be, please? I cannot see anything in the configuration for OpenDKIM or Postfix that might allow just those messages to go out unsigned.

In case it is relevant/important, this system is running:

mailman 3.3.5 mailman-hyperkitty 1.2.0 mailman-web 0.0.5 mailmanclient 3.3.3

Thank you.

Regards

Philip