# Mail-Tester: how AI models rank it, October 2026

GTM AI Recommendation Index, October 2026 Edition. Named in 20 judge labels across 1 categories by 11 of 14 models. Page: https://gtm-ai-index.com/vendors/mail-tester/

## Standing by category

| Category | Share | Rank | Negative rate | Labels |
|---|---|---|---|---|
| Email deliverability and testing tools | 5% | 5 | 25% | 20 |

## What the models said for it

- "Mail-Tester for occasional pre-send checks of a message and its sending setup. It allows up to 3 free tests per day." (GPT-6 Luna, Email deliverability)
- "The best email deliverability tool for a company with a limited budget is Mail-Tester or Unspam for pre-send testing" (Llama 4 Maverick, Email deliverability)
- "Start with free tools → Google Postmaster Tools + MXToolbox + Mail-Tester free tier" (Kimi K2, Email deliverability)
- "Best for: Fast, free, one-off deliverability checks... However, it lacks the deep inbox-by-inbox placement data of GlockApps." (Gemini 3.5 Flash, Email deliverability)

## And against it

- "Mail-Tester scores against a single seed address, so it can't tell you where your email lands across a multi-ISP seed network" (Claude Haiku 4.5, Email deliverability)
- "These are inaccurate and misleading... do not base business decisions on them." (DeepSeek V4 Flash, Email deliverability)
- "Avoid: Relying solely on these web-based scores. They are useful for a quick syntax check but should not be your primary deliverability testing tool." (GLM 4.7 FlashX, Email deliverability)
- "Free tools like Mail Tester and MxToolbox handle basic checks but lack the depth for production workflows." (Muse Glimmer 30B, Email deliverability)

## What it publishes

Every page mailtester.com exposes, read 2026-09-29: 10428 addresses. By kind, pages and the last 90 days:

- blog: 9795 pages, 31 in the last 90 days, latest 2026-09-27
- case study: 4 pages, 4 in the last 90 days, latest 2026-09-21
- webinar or virtual event: 6 pages, 6 in the last 90 days, latest 2026-09-03
- conference or event: 2 pages, 2 in the last 90 days, latest 2026-09-05
- report or ebook: 1 pages, 1 in the last 90 days, latest 2026-08-10
- comparison: 460 pages, 77 in the last 90 days, latest 2026-09-27
- template or tool: 63 pages, 31 in the last 90 days, latest 2026-09-27
- glossary or explainer: 61 pages, 27 in the last 90 days, latest 2026-09-19
- podcast or video: 18 pages, 18 in the last 90 days, latest 2026-08-25
- news or press: 3 pages, 3 in the last 90 days, latest 2026-08-31
- Recent: 2026-09-27 comparison: Predictive analytics email validation one time vs subscribers https://mailtester.com/blog/predictive-analytics-email-validation-one-time-vs-subscribers
- Recent: 2026-09-27 blog: Using email validation to clean dormant lists for reactivation https://mailtester.com/blog/using-email-validation-to-clean-dormant-lists-for-reactivation
- Recent: 2026-09-27 blog: Email verification service features classify buyers purchase frequency https://mailtester.com/blog/email-verification-service-features-classify-buyers-purchase-frequency
- Recent: 2026-09-27 blog: Building re engagement sequences with verified high quality emails https://mailtester.com/blog/building-re-engagement-sequences-with-verified-high-quality-emails
- Recent: 2026-09-27 blog: Email address validation in non production environments safely https://mailtester.com/blog/email-address-validation-in-non-production-environments-safely
- Recent: 2026-09-27 blog: Set up email records cloudflare proxy https://mailtester.com/blog/set-up-email-records-cloudflare-proxy

## Record

- Method: https://gtm-ai-index.com/methodology/
- Raw judge labels and full responses: https://gtm-ai-index.com/data/
- License: CC BY 4.0. Cite as GTM AI Recommendation Index, October 2026 Edition, gtm-ai-index.com.