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Email deliverability and testing tools · October 2026 Edition

GlockApps vs MXToolbox

Nine of fourteen models named GlockApps first on the direct prompt; zero named MXToolbox. GlockApps was named by fourteen of the fourteen models and MXToolbox by twelve and GlockApps carries 57 labels and MXToolbox 31, so the shares are not directly comparable.

GlockApps

endorsed leader

Named in one category this edition.

MXToolbox

accepted challenger

Named in two categories this edition.

First-choice share34%5%Of first choices across the direct, paraphrase, budget and scale prompts, 0 to 100.
Negative rate7%10%Negative labels as a share of the product's labels, 0 to 100.
Rank in category#1#4A position in a field of 12; printed, not drawn.
Labels5731A count; the two differ.
The two percentage rows are drawn on one 0 to 100 track, GlockApps reading right to left. Rank and label count are printed, not drawn.GlockApps vs Google Postmaster Tools · GlockApps vs MailReach · GlockApps vs Mail-Tester

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; rank is within the category; every quote names the model and the prompt it came from. Both figures come from the email deliverability and testing tools page.

By framing

How many of the fourteen models made each the first choice, per way of asking, and how many argued against it.
GlockAppsFirst choices, of fourteen modelsMXToolbox
Direct90
Paraphrase100
Comparative120
Budget-constrained133 against GlockApps
Scale-constrained00
Negative301 against GlockApps · 3 against MXToolbox
Bars are first choices, 0 to 14 each sideModels that argued againstA model can name both, so the two sides of a row do not sum to fourteen.

Across every category in the October 2026 Edition, GlockApps and MXToolbox were named in the same answer fifty-two times, of the 153 answers naming GlockApps and the 72 naming MXToolbox. In those answers MXToolbox took the first choice six times and GlockApps twenty-four.

Every model, every framing

The eighty-four answers behind the chart above, one cell each: where GlockApps and MXToolbox stood in it.
ModelDirectParaphraseComparativeBudget-constrainedScale-constrainedNegative
Claude Haiku 4.5
GPT-5.4 mini
Gemini 3.5 Flash
Perplexity Sonar
Grok 4.1 Fast
Mistral Small
DeepSeek V4 Flash
Llama 4 Maverick
Qwen 3.7 Flash
Kimi K2
GLM 4.7 FlashX
MiniMax M2.5
GPT-6 Luna
Muse Glimmer 30B
GlockApps MXToolbox first choice named as an alternative argued againstblank: not namedEach cell is one answer, GlockApps on the left and MXToolbox on the right.

The direct prompt

The plain question, one answer per model, grouped by where GlockApps and MXToolbox stood in it.

GlockApps first, MXToolbox not the choice

9 of 14 modelsMXToolbox was named in the answer but not as the choice, or not at all.
Gemini 3.5 FlashAllegrow, GlockApps alternatives: Mailgun Optimize, ZeroBounce
Perplexity SonarGlockApps alternatives: Amplemarket, MailReach, NeverBounce
Grok 4.1 FastGlockApps alternatives: MailReach, Validity Everest, Warmy.io
Mistral SmallFolderly, GlockApps alternatives: MailReach, Zoho CRM
Llama 4 MaverickGlockApps
Qwen 3.7 FlashGlockApps alternatives: 250ok, Instantly, Kickbox, Lemlist, Valimail, ZeroBounce
Kimi K2GlockApps, Instantly alternatives: HubSpot Sales Hub, MailReach
GLM 4.7 FlashXGlockApps, MailReach alternatives: Folderly, Warmy
Muse Glimmer 30BGlockApps alternatives: MailReach, Validity Everest

Neither was the first choice, one was named

5 of 14 modelsThe answer put something else first and named one of the two as an alternative.
Claude Haiku 4.5InboxArmy, MailBrace alternatives: Folderly, GlockApps, HubSpot, Mailsoftly
GPT-5.4 miniMailgun Optimize alternatives: GlockApps
DeepSeek V4 FlashMailReach alternatives: GlockApps, Google Postmaster Tools, MXToolbox
MiniMax M2.5Folderly, Mailtrap alternatives: EasyDMARC, MXToolbox
GPT-6 LunaValidity Everest alternatives: GlockApps

Bold names in an answer are the products the judge labeled a first choice; a model naming several gives each of them that label. The full answer text for every row is in the record.

By buyer segment

The same question asked on behalf of a different buyer. Each standing is computed within its segment and they are never added together. The figures above are the mid-market standing, which is the one the category orders by.
Small business
GlockApps leads by eighteen points.
GlockApps24%#1 of 15
MXToolbox6%#3 of 15
The full small business standing →
Mid-marketThe figures above
GlockApps leads by twenty-nine points.
GlockApps34%#1 of 12
MXToolbox5%#4 of 12
The full mid-market standing →
Enterprise
GlockApps leads by two points.
GlockApps2%#5 of 14
MXToolbox0%#14 of 14
The full enterprise standing →

What the models said about GlockApps

Every negative label with a quote, up to three, then the highest-weighted positives, up to three. Six of eight in this category shown.

“GlockApps became popular for one specific capability... Test credits do not roll over... stops at telling you what is wrong.” Muse Glimmer 30B · negative prompt · soft negative
“a fraction of what enterprise tools like GlockApps ($85+/month) or ZeroBounce ($99/month) would cost” DeepSeek V4 Flash · budget prompt · soft negative
“Good for deeper testing, but pricier; consider only if you have repeated deliverability issues” GLM 4.7 FlashX · budget prompt · soft negative
“For most mid-sized B2B companies, GlockApps offers the best balance of comprehensive diagnostics, B2B-appropriate seed lists, and reasonable pricing.” Claude Haiku 4.5 · paraphrase prompt · first choice
“the best choice is usually GlockApps if you want the strongest balance of inbox placement testing, DMARC monitoring, and mid-market pricing” Perplexity Sonar · direct prompt · first choice
“For most mid-sized B2B companies, GlockApps is the best choice due to its depth of inbox placement testing and deliverability diagnostics.” Mistral Small · paraphrase prompt · first choice

What the models said about MXToolbox

Every negative label with a quote, up to three, then the highest-weighted positives, up to three. Six of seven in this category shown.

“MxToolbox is an infrastructure diagnostic tool, not a campaign email testing tool... best used only for specific DNS and infrastructure checks, not comprehensive campaign testing.” Claude Haiku 4.5 · negative prompt · hard negative
“Free tools like Mail Tester and MxToolbox handle basic checks but lack the depth for production workflows.” Muse Glimmer 30B · negative prompt · soft negative
“lack depth for production-scale testing, inbox placement simulation, or ongoing monitoring” Grok 4.1 Fast · negative prompt · soft negative
“Best free option: Stack Google Postmaster Tools, Microsoft SNDS, Yahoo Sender Hub, MXToolbox, Mail Tester, AboutMyEmail, and Sender Hub.” GLM 4.7 FlashX · budget prompt · first choice
“free monitoring stack with Google Postmaster Tools, Microsoft SNDS, MXToolbox, and Yahoo Sender Hub” Perplexity Sonar · budget prompt · first choice
“Start with free tools → Google Postmaster Tools + MXToolbox + Mail-Tester free tier” Kimi K2 · budget prompt · first choice
Also compared

Comparisons are drawn for the top eight products in each category, each against each. The output is the models' output; nothing here is a recommendation by the index.