How exactly does one disable the DMARC support?
I.e., adding INCLUDE_DMARC: false to the env section of mail-receiver.yml does not seem to do it. This does appear to cause the opendkim and opendmarc daemons to not run (leading to a warning in the logs), but SPF checking is still being performed.
Edited to add:
I think I managed to disable the SPF checks by also adding the following POSTCONF_ line to the env section:
env:
...
INCLUDE_DMARC: false
POSTCONF_smtpd_recipient_restrictions: check_policy_service unix:private/policy
...
I got this by looking at the commit which introduced the DMARC checks, and seeing what should happen when INCLUDE_DMARC is false.
I know next-to-nothing about how docker images are built, but I am getting the impression that the INCLUDE_DMARC flag is something meant to be set by someone else, somewhere else, at some other time — not something that can be done in mail-receiver.yml.