Added a Sub-configuration option to fail if the DNSSEC validation for the requested SRV record fails, i.e. if the AD flag is not set, then assume there is no valid HKP server for this domain. If this option is not set, then the lack of validation is logged, but the lookup to the HKP server still takes place as normal. This enables the administrator to check for potential failures in the logs before enabling hard-fail.

# OX Guard performs a SRV lookup on a recipient's domain in order to query the related HKP server.
# This option controls whether or not OX Guard trusts unsigned SRV DNS records. Default is true.
# If set to false, OX Guard will discard unsigned DNS SRV records. Other DNS requests than SRV are not affected.
com.openexchange.guard.dns.allowUnsignedSRVRecords =true