SPF Flattener
SPF Record Flattener
Resolve all include: mechanisms and produce a single flat record with zero DNS lookups, staying within the SPF limit of 10.
Enter your domain above to flatten its SPF record
About this tool
- Why does SPF have a 10-lookup limit?
- RFC 7208 limits SPF evaluation to 10 DNS lookups to prevent denial-of-service via recursive records. Modern email setups using Gmail, Microsoft 365, Mailchimp, and SendGrid together easily exceed this limit.
- What happens when you exceed 10 lookups?
- The SPF check returns permerror. Many receiving servers treat permerror the same as fail, meaning your legitimate mail may be rejected or marked as spam — even though your record looks correct.
- What is a hosted flat record?
- Instead of multiple include: entries in your SPF record, you point to a single Mailvry-hosted record that contains all the resolved IP addresses. Mailvry updates it daily so your SPF stays current as providers change their IPs.
- Does flattening break SPF?
- No. The flat record contains the same IP addresses as the original — just resolved ahead of time rather than at evaluation time. The receiving server sees the same result without burning any lookup budget.