Resolvers obviously can't generate signatures for synthesized responses to ANY queries. So when the DO bit was set, the draft suggests returning unsigned recor

Resolvers obviously can't generate signatures for synthesized responses to ANY queries. So when the DO bit was set, the draft suggests returning unsigned records, because the initiator can then explicitly ask for HINFO and get a signed response. However, resolvers just return SERVFAIL if the response doesn't validate. Will Qmail retry with more specific records after a SERVFAIL response code?