checkdmarc 5.15.1

on Python PyPI

Changes

• Revert the 5.15.0 default of auto-configuring public nameservers
  (1.1.1.1, 8.8.8.8) when no nameservers are passed. When nameservers
  is None, checkdmarc now falls back to the system-configured resolvers
  again (/etc/resolv.conf on Linux/macOS, the OS resolver on Windows),
  matching the 5.14.x and earlier behavior. The auto-configured default would
  surprise users running split-horizon or internal DNS and broke workflows
  that previously relied on the system resolver.
• Rename the exposed constant from DEFAULT_DNS_NAMESERVERS to
  RECOMMENDED_DNS_NAMESERVERS to reflect that it is an opt-in
  recommendation, not an automatic default. It is re-exported from the
  package root as checkdmarc.RECOMMENDED_DNS_NAMESERVERS so callers can
  easily opt in with
  check_domains(..., nameservers=RECOMMENDED_DNS_NAMESERVERS).
• Documentation now calls out mixing public resolvers from different
  providers as a best practice for public-internet checks.