Methodology
How we research and label comparisons of email warm-up and deliverability tools on deliverabilitymatrix.com — without promising inbox outcomes.
1. Scope (2026-09)
- Public pricing pages, feature docs, and merchant-stated models only unless a dated primary observation is published.
- Living matrix: tables may change when vendors update plans; cells marked ASSUMPTION or “not listed publicly” are not quotes.
- Public merchant pricing pages remain the primary source for list prices cited on comparison pages.
2. Labels we use
- Not listed publicly — no clear self-serve list price for that scale; we do not invent quotes.
- ASSUMPTION — editorial inference (e.g. typical model class) pending merchant-source confirmation.
- Observed [date] — reserved for future limited primary tests with N inboxes + protocol link (none claimed yet).
- Verified [month/year] — captured from a merchant public pricing URL on that stamp.
3. Ranking approach
- Merchants do not pay for higher rankings on this site.
- Comparisons are independent guidance — not advice for your specific setup or a compliance certification.
4. What our comparisons mean
When we cite features or prices, we pull them from the merchant’s public pages and stamp the month we checked. Warm-up and deliverability tools may support healthier sender signals when SPF/DKIM/DMARC and list hygiene are already in place — inbox placement still varies by provider, list quality, content, and domain age.
We don’t promise “guaranteed inbox,” “beat spam filters,” or similar outcomes, and we don’t invent lab results or paid rankings.
5. Update cadence
Methodology stamp for this version: 2026-09. Material pricing or framing changes should bump the stamp and notes on affected comparison pages.