Email deliverability and testing tools
Asked as “email deliverability tool”, and as “inbox placement and email testing platform”, on behalf of a mid-market B2B company. 50 first choices recorded across the direct, paraphrase, budget and scale prompts, fourteen models each. Added to the November 2026 Edition.
Standing · first-choice share
38%
Contested · Google Postmaster Tools 10%
38GlockApps10Google Postmaster Tools10Sender42others
38% of first choices, contested.
Since October 2026▲+4Since October 2026: 34% → 38%, +4 points. Inside the 11-point floor: within noise.GlockApps held the lead, +4 points on 34%, inside the 11-point floor.
By buyer segment
The same question asked on behalf of a different buyer. Each standing is computed within its segment; they sit side by side and are never added together.
Small business
GlockApps25%Contested▲+1Since October 2026: 24% → 25%, +1 point. Inside the 11-point floor: within noise.Standing →Mid-marketGlockApps38%Contested▲+4Since October 2026: 34% → 38%, +4 points. Inside the 11-point floor: within noise.This pageEnterprise
Validity Everest46%Clear leader▲+1Since October 2026: 45% → 46%, +1 point. Inside the 11-point floor: within noise.Standing →
GlockApps25%Contested▲+1Since October 2026: 24% → 25%, +1 point. Inside the 11-point floor: within noise.Standing →Mid-marketGlockApps38%Contested▲+4Since October 2026: 34% → 38%, +4 points. Inside the 11-point floor: within noise.This pageEnterpriseValidity Everest46%Clear leader▲+1Since October 2026: 45% → 46%, +1 point. Inside the 11-point floor: within noise.Standing →The standing
Share is the count of first choices across the direct, paraphrase, budget and scale prompts, over all fourteen models, for a mid-market B2B company. Ordered by share.
ProductFirst-choice shareNegative rateLabelsQuadrantSince October 2026
01GlockApps38%9%57endorsed leader▲+4Since October 2026: 34% → 38%, +4 points. Inside the 11-point floor: within noise.34% → 38%
GlockApps38%9%57endorsed leader▲+4Since October 2026: 34% → 38%, +4 points. Inside the 11-point floor: within noise.34% → 38%02Google Postmaster Tools Lab in the set10%6%34accepted challenger▲+1Since October 2026: 9% → 10%, +1 point. Inside the 11-point floor: within noise.9% → 10%
03
Litmus6%10%21accepted challenger▲+6Since October 2026: 0% → 6%, +6 points. Inside the 11-point floor: within noise.0% → 6%
Litmus6%10%21accepted challenger▲+6Since October 2026: 0% → 6%, +6 points. Inside the 11-point floor: within noise.0% → 6%04
ZeroBounce4%14%28accepted challenger▲+4Since October 2026: 0% → 4%, +4 points. Inside the 11-point floor: within noise.0% → 4%
ZeroBounce4%14%28accepted challenger▲+4Since October 2026: 0% → 4%, +4 points. Inside the 11-point floor: within noise.0% → 4%05
MXToolbox2%6%32accepted challenger▼−3Since October 2026: 5% → 2%, −3 points. Inside the 11-point floor: within noise.5% → 2%
MXToolbox2%6%32accepted challenger▼−3Since October 2026: 5% → 2%, −3 points. Inside the 11-point floor: within noise.5% → 2%06
MailReach2%8%25accepted challenger▼−5Since October 2026: 7% → 2%, −5 points. Inside the 11-point floor: within noise.7% → 2%
MailReach2%8%25accepted challenger▼−5Since October 2026: 7% → 2%, −5 points. Inside the 11-point floor: within noise.7% → 2%07Validity Everest2%22%32accepted challenger▼−1Since October 2026: 3% → 2%, −1 point. Inside the 11-point floor: within noise.3% → 2%
Validity Everest2%22%32accepted challenger▼−1Since October 2026: 3% → 2%, −1 point. Inside the 11-point floor: within noise.3% → 2%08
Mail-Tester2%19%27accepted challenger▼−3Since October 2026: 5% → 2%, −3 points. Inside the 11-point floor: within noise.5% → 2%
Mail-Tester2%19%27accepted challenger▼−3Since October 2026: 5% → 2%, −3 points. Inside the 11-point floor: within noise.5% → 2%09
Folderly2%14%14accepted challenger▼−1Since October 2026: 3% → 2%, −1 point. Inside the 11-point floor: within noise.3% → 2%
Folderly2%14%14accepted challenger▼−1Since October 2026: 3% → 2%, −1 point. Inside the 11-point floor: within noise.3% → 2%10
Mailgun2%10%10accepted challenger▲+2Since October 2026: 0% → 2%, +2 points. Inside the 11-point floor: within noise.0% → 2%
Mailgun2%10%10accepted challenger▲+2Since October 2026: 0% → 2%, +2 points. Inside the 11-point floor: within noise.0% → 2%Show the nine products at 0%, ordered by negative rate
19
Instantly0%30%10criticized challenger▼−2Since October 2026: 2% → 0%, −2 points. Inside the 11-point floor: within noise.2% → 0%
Instantly0%30%10criticized challenger▼−2Since October 2026: 2% → 0%, −2 points. Inside the 11-point floor: within noise.2% → 0%12
Mailtrap Email Sandbox0%13%15accepted challenger▼−2Since October 2026: 2% → 0%, −2 points. Inside the 11-point floor: within noise.2% → 0%
Mailtrap Email Sandbox0%13%15accepted challenger▼−2Since October 2026: 2% → 0%, −2 points. Inside the 11-point floor: within noise.2% → 0%18
Kickbox0%10%10accepted challenger=heldSince October 2026: 0% → 0%, ±0 points. Inside the 11-point floor: within noise.0% → 0%
Kickbox0%10%10accepted challenger=heldSince October 2026: 0% → 0%, ±0 points. Inside the 11-point floor: within noise.0% → 0%16
NeverBounce0%10%10accepted challenger=heldSince October 2026: 0% → 0%, ±0 points. Inside the 11-point floor: within noise.0% → 0%
NeverBounce0%10%10accepted challenger=heldSince October 2026: 0% → 0%, ±0 points. Inside the 11-point floor: within noise.0% → 0%17
Warmup Inbox0%10%10accepted challenger▼−2Since October 2026: 2% → 0%, −2 points. Inside the 11-point floor: within noise.2% → 0%
Warmup Inbox0%10%10accepted challenger▼−2Since October 2026: 2% → 0%, −2 points. Inside the 11-point floor: within noise.2% → 0%15
EasyDMARC0%8%12accepted challenger=heldSince October 2026: 0% → 0%, ±0 points. Inside the 11-point floor: within noise.0% → 0%
EasyDMARC0%8%12accepted challenger=heldSince October 2026: 0% → 0%, ±0 points. Inside the 11-point floor: within noise.0% → 0%14
Email on Acid0%7%14accepted challenger=heldSince October 2026: 0% → 0%, ±0 points. Inside the 11-point floor: within noise.0% → 0%
Email on Acid0%7%14accepted challenger=heldSince October 2026: 0% → 0%, ±0 points. Inside the 11-point floor: within noise.0% → 0%11Microsoft SNDS0%0%17accepted challenger▼−3Since October 2026: 3% → 0%, −3 points. Inside the 11-point floor: within noise.3% → 0%
13
SendForensics0%0%13accepted challenger=heldSince October 2026: 0% → 0%, ±0 points. Inside the 11-point floor: within noise.0% → 0%
SendForensics0%0%13accepted challenger=heldSince October 2026: 0% → 0%, ±0 points. Inside the 11-point floor: within noise.0% → 0%The floor is 11 points of share, measured: how far the models move a leader on their own when the same questions are asked twice with nothing changed. A larger change is movement; a smaller one can't be told apart from repeat variation, and both are shown. Each index measures its own floor from its own repeat, over its own categories, so the floor differs from one index to the next. Both editions asked the same fourteen models. How the floor is measured
Bars are the share of first choices, 0 to 100Every product with at least 10 labels here. Every product name links to its product page.
Google Postmaster Tools is made by Google, whose model Gemini 3.5 Flash is in the set. On the four share prompts that model made it the first choice one time of 4; the other thirteen models four times of 52. Lab treatment is defined on the method page; the row is marked, not excluded.
All twenty-eight head-to-head pages: the top eight products, each against each
GlockApps vs MXToolboxGlockApps vs MailReachGlockApps vs Validity EverestGlockApps vs Mail-TesterGoogle Postmaster Tools vs LitmusGoogle Postmaster Tools vs ZeroBounceGoogle Postmaster Tools vs MXToolboxGoogle Postmaster Tools vs MailReachGoogle Postmaster Tools vs Validity EverestGoogle Postmaster Tools vs Mail-TesterLitmus vs ZeroBounceLitmus vs MXToolboxLitmus vs MailReachLitmus vs Validity EverestLitmus vs Mail-TesterZeroBounce vs MXToolboxZeroBounce vs MailReachZeroBounce vs Validity EverestZeroBounce vs Mail-TesterMXToolbox vs MailReachMXToolbox vs Validity EverestMXToolbox vs Mail-TesterMailReach vs Validity EverestMailReach vs Mail-TesterValidity Everest vs Mail-Tester
Recommended versus criticized
Every product with at least 10 labels here, on both axes. The 30% line names a quadrant, not the verdict above: that one needs more than 40%.
Criticized challengerCriticized default
Negative label rate →
01G02
0304050607080910M11
1213141516171819Accepted challengerEndorsed leader
0%First-choice share → · lines at 30% share and 25% negative50%
Key
01GlockApps38%
GlockApps38%02Google Postmaster Tools10%
03Litmus6%
Litmus6%04ZeroBounce4%
ZeroBounce4%05MXToolbox2%
MXToolbox2%06MailReach2%
MailReach2%07Validity Everest2%
Validity Everest2%08Mail-Tester2%
Mail-Tester2%09Folderly2%
Folderly2%10Mailgun2%
Mailgun2%11Microsoft SNDS0%
12Mailtrap Email Sandbox0%
Mailtrap Email Sandbox0%13SendForensics0%
SendForensics0%14Email on Acid0%
Email on Acid0%15EasyDMARC0%
EasyDMARC0%16NeverBounce0%
NeverBounce0%17Warmup Inbox0%
Warmup Inbox0%18Kickbox0%
Kickbox0%19Instantly0%
Instantly0%What they warned about
Four of fourteen models held their first choice under the paraphrase. Claude Haiku 4.5, GPT-5.4 mini, Gemini 3.5 Flash, Mistral Small, DeepSeek V4 Flash, Llama 4 Maverick, Qwen 3.7 Flash, Kimi K2, MiniMax M2.5 and Muse Glimmer 30B changed. A high negative share on a product with few labels is a warning. A low share on a product with many labels is salience, not sentiment.
Validity Everest22%
7 of 32 labels negative · 5 of 14 models · 1 hard negative
“Unnecessary enterprise tools (Validity Everest, etc.) unless you're at scale.” GLM 4.7 FlashX, budget prompt
GlockApps9%
5 of 57 labels negative · 5 of 14 models
“Seed-list placement testers such as GlockApps, Unspam, or similar tools: useful for directional comparisons, but test accounts do not behave like real subscribers” Perplexity Sonar, negative prompt
Mail-Tester19%
5 of 27 labels negative · 5 of 14 models
“Mail-Tester does one thing well: it runs your email through SpamAssassin and checks your SPF, DKIM, and DMARC records. That's useful. It's also not enough.” Muse Glimmer 30B, negative prompt
ZeroBounce14%
4 of 28 labels negative · 4 of 14 models
“Address-verification services such as ZeroBounce, Kickbox, or comparable vendors: treat results as risk estimates, not proof of consent” Perplexity Sonar, negative prompt
What they cite
Fourteen of the fourteen models returned a source list in this edition: five return the pages they cited and nine the search results they consulted.
Sites the answers cite
72 of 84 answers in this category came back with a source list, from 14 of 14 models: citations where the model returns them, or the search results it consulted. 857 links across 204 sites, every framing counted. Ranked by the number of answers carrying the site or page. 7 of the 252 answers across every segment cited this index's own page for the category; the method page measures whether that reading tilts an answer.
vendor site · Unspam24 answers · 27 citations · 11 models
vendor site · GlockApps23 answers · 44 citations · 10 models
19 answers · 19 citations · 9 models
vendor site · Mailtrap16 answers · 17 citations · 9 models
15 answers · 20 citations · 9 models
15 answers · 17 citations · 9 models
vendor site · MyEmailVerifier15 answers · 15 citations · 9 models
vendor site · MailTester14 answers · 51 citations · 8 models
vendor site · Prospeo14 answers · 19 citations · 7 models
14 answers · 14 citations · 8 models
13 answers · 14 citations · 8 models
vendor site · Omnisend12 answers · 13 citations · 6 models
Pages the answers cite
The ten pages named in the most answers, by full address. A page here is one the models returned with a recommendation, not one the index endorses.
15 answers · 9 models
14 answers · 8 models
14 answers · 8 models
14 answers · 10 models
11 answers · 6 models
11 answers · 7 models
10 answers · 7 models
9 answers · 5 models
9 answers · 5 models
9 answers · 9 models
Search against answers
Each company's standing in the answers beside its site's footprint in Google search, one row a site: the products the models named on it with their shares, and the share they add up to; monthly searches on Google, and DataForSEO's estimate of AI search demand (modeled from search signals, directional, not a count of queries to any assistant), for the most-searched of the company's and its products' names (the name is in each row's hover text); estimated monthly organic visits to the site; and its best position in Google's top ten for “best email deliverability tool”, “email deliverability tool”. US estimates from DataForSEO and Google's Ads Transparency Center. A small company's site, or a mid-sized company's site for its flagship, is marked company; a product on a large parent's site (Google, Microsoft) has no site figures. A column with no figures for this category is left out, and an empty cell means none were seen, not none exist. Two measurements side by side: neither is read as the cause of the other.
| Company and products | Share | Own site cited | Name searches, Google | AI search demand, est. | Organic visits | Paid search a month, est. | Google ads, last 30 days |
|---|---|---|---|---|---|---|---|
| GlockApps glockapps.com | 38% | 144 | 1,600 | 3 | 8,647 | 1 | |
| Google parent site Google Postmaster Tools 10% | 10% | 83 | 6,600 | 24 | |||
| Sender sender.net | 10% | 75 | 9,900 | 10,349 | 69,078 | 13 | |
| Litmus litmus.com | 6% | 56 | 12,100 | 2,310 | 38,533 | 15 | |
| ZeroBounce zerobounce.net | 4% | 250 | 9,900 | 118 | 38,183 | $778 | 120 |
| Allegrow allegrow.co | 4% | 11 | |||||
| HubSpot parent site HubSpot Sales Hub 4% | 4% | 687 | 368,000 | 9,776 | |||
| Validity validity.com Validity Everest 2%, Validity Engage 2% | 4% | 73 | 140 | 0 | 24,467 company | $264 | 120 |
| Unspam unspam.email Unspam.email 2%, Unspam 2% | 4% | 20 | |||||
| MXToolbox mxtoolbox.com | 2% | 75 | 60,500 | 126 | 453,570 | 18 |
Google's top ten for the two searches hold 17 sites; 1 of them are among the sites the models cited here (mailtester.com). The first result for “best email deliverability tool” is devopsschool.com.
How they answered
Six framings of the same buying question, each sent to every model in a fresh session with search on. One row per model, so a row shows whether it held its answer under rewording, what it named when cost was the constraint, and what it argued against. Computed from the raw judge labels.ShowHide
How they answered
Six framings of the same buying question, each sent to every model in a fresh session with search on. One row per model, so a row shows whether it held its answer under rewording, what it named when cost was the constraint, and what it argued against. Computed from the raw judge labels.
ShowHideModelDirect“What is the best email deliverability tool for a mid-market B2B company?”Paraphrase“Which inbox placement and email testing platform would you recommend to a mid-sized B2B company?”Comparative“What are the top email deliverability and testing tools and how do they differ?”Budget-constrained“What is the best email deliverability tool for a company with a limited budget?”Scale-constrained“We are a 500 person company evaluating an email deliverability tool. What should we look at?”Negative“Which email deliverability and testing tools should I avoid or be cautious about?”
Claude Haiku 4.5WarmyMailReachChangedMailtrap Email SandboxGoogle Postmaster Tools, MXToolboxno first choiceagainst: Folderly, GlockApps, Guerrilla Mail, Mail-Tester, Mailinator, Temp Mail
Four alternatives
Act-On, GlockApps, MailReach, Mailtrap Email MarketingThree alternatives
Folderly, GlockApps, WarmyFive alternatives
Folderly, GlockApps, Google Postmaster Tools, Litmus, MailReachOne alternative
GlockAppsGPT-5.4 miniLitmusGlockApps, LitmusChangedGlockApps, Litmusagainst: Google Postmaster ToolsMailgun, Postmarkno first choiceagainst: Mailtrap Email Sandbox, www.mail-tester.com
Four alternatives
Brevo, HubSpot, Salesforce/Marketing Cloud, ZeroBounceSix alternatives
EasyDMARC, Email on Acid, InboxAlly, Mailtrap Email Sandbox, Validity Everest, ZeroBounceGemini 3.5 FlashGlockAppsagainst: Validity EverestLitmusChangedagainst: Validity EverestFolderly, GlockAppsGoogle Postmaster Toolsagainst: Inbox Monster, Validity Everestno first choiceagainst: SpamAssassin
Five alternatives
Folderly, Google Postmaster Tools, Mailgun Optimize, Mailtrap Email Sandbox, Microsoft Smart Network Data Services (SNDS) / Microsoft 365 Admin InsightsTwo alternatives
Email on Acid, GlockAppsSeven alternatives
Email on Acid, Litmus, MXToolbox, Mail-Tester, NeverBounce, Validity Everest, ZeroBounceNine alternatives
DeBounce, GlockApps, Instantly, MXToolbox, Mail-Tester, Smartlead, TrulyInbox, Warmup Inbox, ZeroBouncePerplexity SonarGlockAppsGlockAppsHeldGlockAppsSenderno first choiceagainst: GlockApps, Google Postmaster Tools, Heatwave, Kickbox, MXToolbox, Mail-Tester, Unspam, ZeroBounce
Eight alternatives
EasyDMARC, Google Postmaster Tools, MailReach, Microsoft SNDS, NeverBounce, Validity Everest, ZeroBounce, dmarcianFive alternatives
Google Postmaster Tools, MailReach, Mailtrap Email Sandbox, Microsoft SNDS, Validity EverestFourteen alternatives
EasyDMARC, Email on Acid, Google Postmaster Tools, Litmus, MXToolbox, MailReach, Mailgun Optimize, Mailtrap Email Sandbox, Microsoft SNDS, NeverBounce, Validity Everest, Warmup Inbox, ZeroBounce, dmarcianFour alternatives
Google Postmaster Tools, MXToolbox, Mail-Tester, MailerCheckGrok 4.20GlockAppsGlockAppsHeldagainst: Return Path, Validity EverestGlockApps, MXToolboxGoogle Postmaster Toolsagainst: Instantly, Warmyno first choiceagainst: EasyDMARC, EmailDeliverability.com, Instantly, MXToolbox, Mail-Tester, MailReach, Mailwarm, Sender Score, Warmy
Two alternatives
Allegrow, Validity EverestFour alternatives
Folderly, Mailtrap Email Sandbox, Unspam.email, ZeroBounceEleven alternatives
EasyDMARC, Google Postmaster Tools, Inbox Monster, Mail-Tester, MailReach, Mailtrap Email Delivery Platform, SendForensics, Sender Score, Unspam.email, Validity Everest, ZeroBounce DeliverabilityThree alternatives
Brevo, GlockApps, MXToolboxSix alternatives
GlockApps, Inbox Radar, Postmark, Saleshandy Inbox Radar, SendGrid, Warmup InboxMistral SmallAllegrow, Validity Everestagainst: Clearout, ZeroBounceGlockAppsChangedGlockApps, Validity EverestSenderno first choicenothing named
One alternative
LitmusThree alternatives
Google Postmaster Tools, Prospeo, ZeroBounceFive alternatives
Email on Acid, Google Postmaster Tools, Litmus, Mail-Tester, Mailtrap Email SandboxTwo alternatives
MailerLite, ProspeoDeepSeek V4 FlashHubSpot Sales HubGlockAppsChangedagainst: LitmusGlockAppsUnspam.emailGlockAppsagainst: Everest, Validity Everestagainst: Email List Validation, GlockApps, Mail-Tester
Seven alternatives
GlockApps, Klaviyo, Lemlist, Mailgun, Outreach, Salesloft, SendGridTwo alternatives
Folderly, ZeroBounceTen alternatives
EasyDMARC, Email on Acid, Folderly, Google Postmaster Tools, Litmus, MXToolbox, Mail-Tester, MailReach, Validity Everest, ZeroBounceSix alternatives
Email Detective, GlockApps, Google Postmaster Tools, Mail-Tester, Sender, Warmup InboxFive alternatives
EasyDMARC, Google Postmaster Tools, Microsoft SNDS, ZeroBounce, dmarcianLlama 4 MaverickGlockAppsno first choiceChangedno first choiceSenderValidity Engagenothing named
Two alternatives
MailReach, Validity EverestQwen 3.7 FlashGlockApps, ZeroBounceFolderlyChangedGoogle Postmaster Tools, MailerCheckno first choiceno first choicenothing named
Six alternatives
Kickbox, NeverBounce, Red Sift OnDMARC, SendForensics, Suped, Validity EverestTwo alternatives
GlockApps, Unspam.emailFour alternatives
GlockApps, Litmus, MX Toolbox, Mailtrap Email SandboxEight alternatives
EasyDMARC, GlockApps, Google Postmaster Tools, MXToolbox, Mail Genius, Mail-Tester, Microsoft SNDS, UnspamKimi K2AllegrowGlockAppsChangedagainst: Email on Acid, Litmusno first choiceMail-Tester, Unspamno first choiceagainst: Email List Validation, Mailinator, MyEmailVerifier, NeverBounce, TempMail, ZeroBounce
Two alternatives
GlockApps, MailReachOne alternative
SendForensicsSeven alternatives
Email Industries, GlockApps, Google Postmaster Tools, MXToolbox, Mail-Tester, MailReach, Validity EverestThree alternatives
Mailchimp, MailerCheck, ZeroBounceGLM 4.7 FlashXGlockAppsGlockAppsHeldno first choiceGoogle Postmaster Toolsagainst: GlockApps, Instantly, Lemlist, Validity Everest, Warmup Inboxno first choicenothing named
Two alternatives
Allegrow, MailReachTwo alternatives
Email on Acid, InstantlyTwelve alternatives
Email Detective, GlockApps, Google Postmaster Tools, Kickbox, Litmus, MXToolbox, Mailgun Validate, NeverBounce, Postmark DMARC Digests, SendForensics, Validity Everest, ZeroBounceSix alternatives
Constant Contact, Folderly, Kickbox, MXToolbox, Mail‑Tester, MoosendMiniMax M2.5HubSpot Sales Hub, ZeroBounceGlockAppsChangedGlockApps, SendForensicsSenderagainst: ZeroBounceno first choiceagainst: Folderly, Lemwarm standalone
Three alternatives
Copper, GlockApps, MXToolboxThree alternatives
Litmus, MailReach, Validity EverestSix alternatives
Email on Acid, Folderly, Litmus, MXToolbox, Mailtrap Email Sandbox, Unspam.emailFour alternatives
Instantly, MXToolbox, MyEmailVerifier, Warmup InboxGPT-6 LunaGlockAppsGlockAppsHeldGlockAppsGoogle Postmaster Toolsno first choicenothing named
Two alternatives
Google Postmaster Tools, Validity EngageOne alternative
Validity EngageSeven alternatives
Email on Acid, Google Postmaster Tools, Litmus, Mailtrap Email Sandbox, Microsoft SNDS, Validity Engage, ZeroBounceOne alternative
GlockAppsMuse Glimmer 30BGlockApps, MailGeniusGlockAppsChangedagainst: Validity EverestGlockAppsSenderno first choiceagainst: GlockApps, Mail-Tester, MailReach, Mailgun, Mailtrap Email Sandbox, SendGrid
Two alternatives
Allegrow, AmplemarketSix alternatives
Google Postmaster Tools, MXToolbox, Mail-Tester, MailReach, Microsoft SNDS, Yahoo Sender HubEight alternatives
EasyDMARC, Email Detective, Google Postmaster Tools, Mail-Tester, PowerDMARC, Unspam, Warmup Inbox, ZeroBounceThree alternatives
Google Postmaster Tools, MXToolbox, Mail-TesterTwo alternatives
Google Postmaster Tools, MXToolboxBold is the first choiceAlternatives are counted; the count opens them.What the answer argued against
The record
One row per call: the version string exactly as returned, whether the model searched, sources cited, and latency.
Eighty-four rows: every prompt, every model, every answer.
| Prompt | Model | Version string | Time (UTC) | Searched | Sources | Latency |
|---|---|---|---|---|---|---|
| Direct recommendation | Claude Haiku 4.5 | claude-haiku-4-5-20251001 | 2026-11-01 15:12 | yes | 19 | 9 s |
| Direct recommendation | GPT-5.4 mini | gpt-5.4-mini-2026-03-17 | 2026-11-01 11:55 | yes | 2 | 5 s |
| Direct recommendation | Gemini 3.5 Flash | gemini-3.6-flash (asked for gemini-3.5-flash; the API answered as this version) | 2026-11-01 11:48 | yes | 13 | 21 s |
| Direct recommendation | Perplexity Sonar | sonar | 2026-11-01 14:26 | yes | 10 | 4 s |
| Direct recommendation | Grok 4.20 | spacexai/grok-4.20-non-reasoning via xai | 2026-11-01 16:43 | yes | 12 | 29 s |
| Direct recommendation | Mistral Small | mistral/mistral-small via mistral | 2026-11-01 17:17 | yes | 5 | 4 s |
| Direct recommendation | DeepSeek V4 Flash | deepseek/deepseek-v4-flash via deepinfra | 2026-11-01 09:55 | no | 0 | 12 s |
| Direct recommendation | Llama 4 Maverick | meta/llama-4-maverick via bedrock | 2026-11-01 13:13 | yes | 5 | 3 s |
| Direct recommendation | Qwen 3.7 Flash | alibaba/qwen3.7-flash via alibaba | 2026-11-01 10:59 | yes | 20 | 30 s |
| Direct recommendation | Kimi K2 | moonshotai/kimi-k2 via novita | 2026-11-01 12:53 | yes | 20 | 29 s |
| Direct recommendation | GLM 4.7 FlashX | zai/glm-4.7-flashx via zai | 2026-11-01 15:10 | yes | 15 | 44 s |
| Direct recommendation | MiniMax M2.5 | minimax/minimax-m2.5 via minimax | 2026-11-01 10:29 | yes | 5 | 24 s |
| Direct recommendation | GPT-6 Luna | gpt-6-luna | 2026-11-01 10:21 | yes | 3 | 13 s |
| Direct recommendation | Muse Glimmer 30B | meta/muse-glimmer-30b via togetherai | 2026-11-01 17:09 | yes | 20 | 28 s |
| Paraphrase | Claude Haiku 4.5 | claude-haiku-4-5-20251001 | 2026-11-01 11:34 | yes | 19 | 10 s |
| Paraphrase | GPT-5.4 mini | gpt-5.4-mini-2026-03-17 | 2026-11-01 16:27 | yes | 3 | 5 s |
| Paraphrase | Gemini 3.5 Flash | gemini-3.6-flash (asked for gemini-3.5-flash; the API answered as this version) | 2026-11-01 08:52 | no | 0 | 19 s |
| Paraphrase | Perplexity Sonar | sonar | 2026-11-01 08:39 | yes | 10 | 3 s |
| Paraphrase | Grok 4.20 | spacexai/grok-4.20-non-reasoning via xai | 2026-11-01 17:24 | yes | 5 | 8 s |
| Paraphrase | Mistral Small | mistral/mistral-small via mistral | 2026-11-01 09:12 | yes | 5 | 4 s |
| Paraphrase | DeepSeek V4 Flash | deepseek/deepseek-v4-flash via deepinfra | 2026-11-01 10:42 | yes | 24 | 22 s |
| Paraphrase | Llama 4 Maverick | meta/llama-4-maverick via bedrock | 2026-11-01 14:25 | yes | 5 | 3 s |
| Paraphrase | Qwen 3.7 Flash | alibaba/qwen3.7-flash via alibaba | 2026-11-01 09:05 | yes | 5 | 29 s |
| Paraphrase | Kimi K2 | moonshotai/kimi-k2 via novita | 2026-11-01 10:16 | yes | 25 | 26 s |
| Paraphrase | GLM 4.7 FlashX | zai/glm-4.7-flashx via zai | 2026-11-01 09:39 | yes | 24 | 51 s |
| Paraphrase | MiniMax M2.5 | minimax/minimax-m2.5 via minimax | 2026-11-01 15:27 | yes | 24 | 42 s |
| Paraphrase | GPT-6 Luna | gpt-6-luna | 2026-11-01 14:24 | yes | 2 | 15 s |
| Paraphrase | Muse Glimmer 30B | meta/muse-glimmer-30b via togetherai | 2026-11-01 15:09 | yes | 15 | 20 s |
| Comparative | Claude Haiku 4.5 | claude-haiku-4-5-20251001 | 2026-11-01 13:50 | yes | 18 | 12 s |
| Comparative | GPT-5.4 mini | gpt-5.4-mini-2026-03-17 | 2026-11-01 10:37 | yes | 5 | 8 s |
| Comparative | Gemini 3.5 Flash | gemini-3.6-flash (asked for gemini-3.5-flash; the API answered as this version) | 2026-11-01 11:58 | no | 0 | 16 s |
| Comparative | Perplexity Sonar | sonar | 2026-11-01 10:54 | yes | 10 | 8 s |
| Comparative | Grok 4.20 | spacexai/grok-4.20-non-reasoning via xai | 2026-11-01 15:35 | yes | 5 | 17 s |
| Comparative | Mistral Small | mistral/mistral-small via mistral | 2026-11-01 15:32 | yes | 10 | 10 s |
| Comparative | DeepSeek V4 Flash | deepseek/deepseek-v4-flash via deepinfra | 2026-11-01 11:22 | yes | 25 | 32 s |
| Comparative | Llama 4 Maverick | meta/llama-4-maverick via bedrock | 2026-11-01 11:47 | yes | 5 | 3 s |
| Comparative | Qwen 3.7 Flash | alibaba/qwen3.7-flash via alibaba | 2026-11-01 16:27 | no | 0 | 28 s |
| Comparative | Kimi K2 | moonshotai/kimi-k2 via novita | 2026-11-01 13:14 | yes | 10 | 23 s |
| Comparative | GLM 4.7 FlashX | zai/glm-4.7-flashx via zai | 2026-11-01 13:13 | yes | 14 | 32 s |
| Comparative | MiniMax M2.5 | minimax/minimax-m2.5 via minimax | 2026-11-01 14:44 | yes | 24 | 55 s |
| Comparative | GPT-6 Luna | gpt-6-luna | 2026-11-01 09:38 | yes | 8 | 23 s |
| Comparative | Muse Glimmer 30B | meta/muse-glimmer-30b via togetherai | 2026-11-01 12:28 | yes | 15 | 23 s |
| Budget constrained | Claude Haiku 4.5 | claude-haiku-4-5-20251001 | 2026-11-01 16:11 | yes | 10 | 8 s |
| Budget constrained | GPT-5.4 mini | gpt-5.4-mini-2026-03-17 | 2026-11-01 14:24 | yes | 3 | 4 s |
| Budget constrained | Gemini 3.5 Flash | gemini-3.6-flash (asked for gemini-3.5-flash; the API answered as this version) | 2026-11-01 11:22 | yes | 7 | 19 s |
| Budget constrained | Perplexity Sonar | sonar | 2026-11-01 12:53 | yes | 10 | 3 s |
| Budget constrained | Grok 4.20 | spacexai/grok-4.20-non-reasoning via xai | 2026-11-01 14:21 | yes | 5 | 9 s |
| Budget constrained | Mistral Small | mistral/mistral-small via mistral | 2026-11-01 15:18 | yes | 5 | 4 s |
| Budget constrained | DeepSeek V4 Flash | deepseek/deepseek-v4-flash via deepinfra | 2026-11-01 14:54 | yes | 18 | 24 s |
| Budget constrained | Llama 4 Maverick | meta/llama-4-maverick via bedrock | 2026-11-01 10:44 | yes | 5 | 2 s |
| Budget constrained | Qwen 3.7 Flash | alibaba/qwen3.7-flash via alibaba | 2026-11-01 16:01 | yes | 5 | 21 s |
| Budget constrained | Kimi K2 | moonshotai/kimi-k2 via novita | 2026-11-01 13:30 | yes | 5 | 14 s |
| Budget constrained | GLM 4.7 FlashX | zai/glm-4.7-flashx via zai | 2026-11-01 13:53 | yes | 15 | 72 s |
| Budget constrained | MiniMax M2.5 | minimax/minimax-m2.5 via minimax | 2026-11-01 10:32 | yes | 14 | 56 s |
| Budget constrained | GPT-6 Luna | gpt-6-luna | 2026-11-01 14:36 | yes | 3 | 10 s |
| Budget constrained | Muse Glimmer 30B | meta/muse-glimmer-30b via togetherai | 2026-11-01 15:19 | yes | 12 | 22 s |
| Scale constrained | Claude Haiku 4.5 | claude-haiku-4-5-20251001 | 2026-11-01 17:23 | no | 0 | 7 s |
| Scale constrained | GPT-5.4 mini | gpt-5.4-mini-2026-03-17 | 2026-11-01 13:24 | no | 0 | 5 s |
| Scale constrained | Gemini 3.5 Flash | gemini-3.6-flash (asked for gemini-3.5-flash; the API answered as this version) | 2026-11-01 12:52 | no | 0 | 15 s |
| Scale constrained | Perplexity Sonar | sonar | 2026-11-01 14:44 | yes | 10 | 9 s |
| Scale constrained | Grok 4.20 | spacexai/grok-4.20-non-reasoning via xai | 2026-11-01 16:18 | yes | 5 | 15 s |
| Scale constrained | Mistral Small | mistral/mistral-small via mistral | 2026-11-01 09:21 | no | 0 | 9 s |
| Scale constrained | DeepSeek V4 Flash | deepseek/deepseek-v4-flash via deepinfra | 2026-11-01 09:34 | yes | 19 | 35 s |
| Scale constrained | Llama 4 Maverick | meta/llama-4-maverick via bedrock | 2026-11-01 13:44 | yes | 5 | 3 s |
| Scale constrained | Qwen 3.7 Flash | alibaba/qwen3.7-flash via alibaba | 2026-11-01 16:27 | no | 0 | 29 s |
| Scale constrained | Kimi K2 | moonshotai/kimi-k2 via novita | 2026-11-01 12:39 | no | 0 | 63 s |
| Scale constrained | GLM 4.7 FlashX | zai/glm-4.7-flashx via zai | 2026-11-01 16:18 | yes | 15 | 42 s |
| Scale constrained | MiniMax M2.5 | minimax/minimax-m2.5 via minimax | 2026-11-01 12:00 | no | 0 | 12 s |
| Scale constrained | GPT-6 Luna | gpt-6-luna | 2026-11-01 16:38 | yes | 3 | 15 s |
| Scale constrained | Muse Glimmer 30B | meta/muse-glimmer-30b via togetherai | 2026-11-01 11:29 | yes | 13 | 17 s |
| Negative framing | Claude Haiku 4.5 | claude-haiku-4-5-20251001 | 2026-11-01 14:38 | yes | 17 | 9 s |
| Negative framing | GPT-5.4 mini | gpt-5.4-mini-2026-03-17 | 2026-11-01 15:41 | yes | 6 | 6 s |
| Negative framing | Gemini 3.5 Flash | gemini-3.6-flash (asked for gemini-3.5-flash; the API answered as this version) | 2026-11-01 11:21 | no | 0 | 18 s |
| Negative framing | Perplexity Sonar | sonar | 2026-11-01 11:06 | yes | 10 | 4 s |
| Negative framing | Grok 4.20 | spacexai/grok-4.20-non-reasoning via xai | 2026-11-01 16:06 | yes | 15 | 15 s |
| Negative framing | Mistral Small | mistral/mistral-small via mistral | 2026-11-01 09:42 | yes | 5 | 5 s |
| Negative framing | DeepSeek V4 Flash | deepseek/deepseek-v4-flash via deepinfra | 2026-11-01 15:18 | yes | 25 | 44 s |
| Negative framing | Llama 4 Maverick | meta/llama-4-maverick via bedrock | 2026-11-01 15:40 | yes | 5 | 2 s |
| Negative framing | Qwen 3.7 Flash | alibaba/qwen3.7-flash via alibaba | 2026-11-01 12:15 | yes | 20 | 49 s |
| Negative framing | Kimi K2 | moonshotai/kimi-k2 via novita | 2026-11-01 09:27 | yes | 25 | 29 s |
| Negative framing | GLM 4.7 FlashX | zai/glm-4.7-flashx via zai | 2026-11-01 09:02 | yes | 23 | 129 s |
| Negative framing | MiniMax M2.5 | minimax/minimax-m2.5 via minimax | 2026-11-01 14:25 | yes | 25 | 71 s |
| Negative framing | GPT-6 Luna | gpt-6-luna | 2026-11-01 15:52 | yes | 5 | 25 s |
| Negative framing | Muse Glimmer 30B | meta/muse-glimmer-30b via togetherai | 2026-11-01 11:45 | yes | 25 | 40 s |
Normalization in this category
Every judgment call made between the raw labels and the numbers above, listed so it is visible and reversible.
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Category-scoped readings
Mailtrap read as Mailtrap Email Sandbox
Validity read as Validity Everest
Validity (Everest) read as Validity Everest
Validity (Return Path) read as Validity Everest
Validity (formerly Return Path) read as Validity Everest
Unresolved, counted raw
AWS SES Sandbox
DMARC Analyzer
Data Axle Inboxable
Email Sandbox
Getsitecontrol Email Quality Checker
Glide Data
Guerrilla Mail
HELO
Heatwave
Inbox Tracker
Inky
Lemwarm standalone
Mail Genius
MailCharts
MailSoar
MailTester.com
Mailcheck.io
Mailhog
Mailivery
Mailtrap Email Delivery Platform
Mail‑Tester
Microsoft Smart Network Data Services (SNDS) / Microsoft 365 Admin Insights
PlusVibe
ReturnPath
Salesforce/Marketing Cloud
Suped
Temp Mail
TempMail
ZeroBounce Deliverability
www.mail-tester.com
Discontinued, still offered
No shut-down product was recommended here.