How to use it
- Tick every service that sends as your domain: your mailbox provider, newsletter tool, CRM, helpdesk, invoicing app and your website's contact form.
- Copy the record and replace your existing SPF TXT record at your DNS host (Cloudflare, GoDaddy, Namecheap and so on).
- Wait a few minutes, then run the email checker to confirm it is valid.
Why the 10-lookup limit matters
Each include, a, mx and exists makes the receiving server do a DNS lookup, and includes can contain more includes. Past 10, receivers stop and treat SPF as broken (permerror) for every email. The counts here are typical values for each service; the checker counts the real number.