methodology / Email & Communications / #82
SPF lookup count (10-limit deliverability check)
#82 · Recommended · Web Quality · weighted · Email & Communications · weight 0.3% · impl implemented · method v1.2.0
Web Quality factor
This factor is part of Web Quality — the weighted 0..100 score that sits above Web Standards. Its weight depends on what kind of site is being measured. Web Standards items take priority; this factor only enters the score once Web Standards passes.
- Base weight
- 1.0 applied to every site type unless overridden below
- Why this weight
- SPF flat-lookup count > 10 silently breaks deliverability. High signal anywhere mail is sent.
Per-site-type overrides
| Site type | Weight | Δ vs base |
|---|---|---|
| Personal site | 0.3 | -0.7 |
Site types not listed inherit the base weight.
What this means for your business
There's a behind-the-scenes ceiling on how many email tools can be authorized to send as your business at once. When you add too many — newsletter, booking, invoicing, helpdesk — you quietly cross the line and all of them start landing in spam.
Plain title: Your email setup is under a hidden limit
What we measure
SPF has a hard limit of 10 DNS lookups. Going over breaks email delivery silently — Gmail and Outlook just refuse the messages. Most domains that hit this limit don't realize until something stops working.
How to improve your score
Use SPF flattening services (or rewrite includes to direct IPs) to stay under the limit. Tools: spf-record.com, easydmarc.
Facts
Implementation notes
Recursively expand `include:` and `redirect=` directives; count total lookups.
Scoring
Scoring formulas are versioned with the methodology. The current method (v1.2.0) maps raw measurements to pass, warn, fail. Factor weights determine how much each contributes to the composite — see the methodology index for the full table.
Cited by these standards
Standards in the Standards Library whose satisfiedBy requirement tree references this factor. Each link goes to the standard's full entry — methodology, scope, and the other factors it relies on.
Version history
| Version | Change | Date |
|---|---|---|
| v1.2.0 | Factor introduced. Status: live. Scoring impl: implemented. | 2026-04-25 |