Unmatched SPF includes top 100

According to Live Direct Marketing's daily Tranco top-1M scan (September 24, 2026), these are the 100 most frequent SPF include: domains that our dictionary does not yet attribute to a named ESP or SaaS sender. Each represents sending infrastructure — often a niche ESP, a hosting provider or a regional platform — worth identifying.

Just as unmatched MX targets mark the frontier of mailbox-provider detection, unmatched SPF includes mark the frontier of sender detection. An include: domain is unmatched when many domains authorize it to send mail but it maps to no known ESP or SaaS platform — typically a niche ESP, a hosting provider's mail relay, or a regional sending service.

Each unmatched include is a piece of real sending infrastructure operating at scale but flying under the radar. Publishing the top of the list is how that infrastructure gets named, and how the ESP and SaaS-sender rankings get more complete over time.

The top 100

Provider-sized clusters to investigate next

Related hostnames are grouped by registrable base domain so one confirmed provider rule can explain several targets at once. Ranked by total occurrences in this snapshot.

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Why unclassified senders are worth naming

An unnamed sender is a blind spot in two directions: the industry cannot measure its reach, and domain owners authorizing it may not realize what it is. Identifying these includes turns a raw SPF token into a known platform — useful for market analysis and for anyone auditing which third parties can send under their domain.

Frequently asked questions