methodology / Email & Communications / #80
Email Service Provider (ESP) detected
#80 · Variable · 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
- 0.4 applied to every site type unless overridden below
- Why this weight
- ESP detection — only meaningful where a newsletter exists.
Per-site-type overrides
| Site type | Weight | Δ vs base |
|---|---|---|
| E-commerce | 0.6 | +0.2 |
| News / Publisher | 0.7 | +0.3 |
| Personal site | 0.0 | -0.4 |
| SaaS / Product | 0.6 | +0.2 |
| Media / Streaming | 0.7 | +0.3 |
Site types not listed inherit the base weight.
What this means for your business
If your business sends marketing email, doing it through a service like Mailchimp or Klaviyo (instead of from your personal inbox) is what keeps you out of spam folders and out of legal trouble with unsubscribe rules.
Plain title: A real tool for sending newsletters
What we measure
We identify whether you're running a real email marketing tool. Detected providers: Mailchimp, ConvertKit, Klaviyo, ActiveCampaign, HubSpot, Substack, Beehiiv, Brevo, Drip, Buttondown. None detected often means you're missing the channel entirely.
How to improve your score
Pick one based on your audience and budget. Mailchimp is the default for most small businesses; ConvertKit for creators; Klaviyo for ecommerce; HubSpot for B2B with sales workflows.
Facts
Implementation notes
Pattern-match script srcs (e.g., `chimpstatic.com`, `convertkit.com`, `klaviyo.com`), form action domains, and known embedded scripts.
When this applies
ESP detection requires a newsletter signup to be present.
- Requires a passing result on factor(s): #79.
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 |