Enter a domain to expand its SPF record — recursively follows all include: and redirect= mechanisms to show every authorised IP subnet in one flat list.
The SPF Record Expander recursively follows all include: and redirect= mechanisms in an SPF record, resolving a: and mx: mechanisms to their IP addresses, and presents the complete list of all subnets that are authorised to send email for a domain. RFC 7208 limits SPF records to 10 DNS-querying mechanisms — this tool counts and warns when that limit is approached or exceeded.