nic@boet.cc Flattens SPF records to stay within the RFC 7208 limits of 10 DNS lookups and 2 void lookups. Resolves the senders a domain lists, replaces lookup terms with aggregated ip4:/ip6: ranges, packs them into a chain of TXT records and verifies the result authorizes the same senders. Also checks published records, imports them into a config, detects drift and scores each source's drift risk. nabbi/spf-flatten