Does MailTester Ninja ever send an email to verify an address?

No. MailTester Ninja never sends a message. It talks to the recipient's SMTP server using commands defined by RFC 821, reads the server's answer, then stops.

What does the free version of MailTester Ninja allow?

The free version verifies one email at a time with no signup required. The number of requests per minute depends on current server load and may be limited to a couple of requests per minute at peak times.

Why do some email addresses return as Catch-All?

Some mail servers accept every incoming address whether the mailbox exists or not, so a specific mailbox cannot be confirmed. MailTester Ninja labels these as Catch-All instead of guessing they are valid, so you keep control.

What are the API rate limits for different plans?

Pro allows 11 requests per 10 seconds (100,000 per day), Ultimate allows 23 requests per 10 seconds (200,000 per day), and a plan quantity multiplies those limits.

What payment methods does MailTester Ninja accept?

Through Stripe, MailTester Ninja accepts most credit and debit cards, Apple Pay, Google Pay, Link, and Bitcoin via the Pay with crypto option.

Fact sheet · Email & notification APIs

MailTester Ninja

Email verification and finder tool that processes data in real time without storage

0 votes. Log in to vote for MailTester Ninja in the file community vote²Follow the file. Log in to follow MailTester Ninja's file Not yet verified by the maker

MailTester Ninja verifies email addresses in real time by checking DNS records and performing SMTP conversations, without ever sending emails or storing data.

Overview

Screenshot of the MailTester Ninja homepage — What mailtester.ninja looks like

MailTester Ninja is a real-time email verification and email finder service built by Unlimited & Limited in London. It validates email addresses by checking DNS records (MX, SPF, DMARC) and performing live SMTP conversations with mail servers, without sending messages or storing data.

The service offers instant email verification for individual addresses, an advanced email finder to discover valid business contacts, anti-spam detection to analyze deliverability scores, and syntax validation. It detects invalid, disposable, and catch-all addresses, and processes verification results with a confidence score and recommendations.

MailTester Ninja is privacy-first by design: email addresses are processed in memory and deleted immediately after analysis, with no permanent storage or data resale. The team has over ten years of experience in email verification and deliverability. The service is available free with single-email verification, and paid plans provide higher volumes and API access.

Feature facts

Real-time email verification checking DNS records and SMTP
Email finder to discover valid business contact addresses
Detects invalid, disposable and catch-all addresses
Anti-spam detection and deliverability analysis
Syntax validation for email format
RESTful API integration for applications
Analytics and reporting of verification results
CSV export and spreadsheet integration
No data storage or retention of verified emails
GDPR compliant privacy-first verification

Pricing

Pricing model: Freemium

Free version verifies one email at a time with no signup. Pro plan: 100,000 emails per day. Ultimate plan: 200,000 emails per day. Plan quantities can be multiplied at checkout; for example Ultimate x5 gives 1,000,000 emails per day. Bitcoin payment accepted via Pay with crypto option.

Follow the file. Log in to follow MailTester Ninja's file

Follow MailTester Ninja: their milestones, new launches and awards come to you by email, once a day by default.

MailTester Ninja specifications

Specifications of MailTester Ninja
Section	Email & notification APIs
Website	mailtester.ninja
Makers	Alexandre (Chief Executive Officer)
Votes²	0

MailTester Ninja metrics

Fact file for mailtester.ninja: Ahrefs Domain Rating and Majestic link facts, each with the change since the last fact check.
Metric	Value
Domain Rating	39 +2 (up) since last check
Trust Flow	14 no change since last check
Citation Flow	32 no change since last check
Referring domains	207 no change since last check
External backlinks	3,599 no change since last check

Fact: Ahrefs Domain Rating checked 12 Nov 2026, fact changed 12 Nov 2026. Fact: top topic Recreation/Food (14). Fact: Majestic checked 25 Oct 2026, fact changed 25 Oct 2026. Link facts from Majestic. Trust Flow, Citation Flow and Topical Trust Flow are trademarks of Majestic-12 Ltd.

MailTester Ninja domain fact sheet

Open the fact sheet

Read from the public RDAP record on 12 Nov 2026, 03:52 UTC.
Domain age	8 years
Registered	3 Oct 2018
Expires	3 Oct 2027
Registrar	OVH SAS
DNSSEC	Signed

Every domain fact for mailtester.ninja

MailTester Ninja launch receipt sheet

What we have measured for MailTester Ninja since it went live on SaaS Directory Info on 25 October 2026.

37 Domain Rating (Ahrefs) no change since launch
at launch: 37 (25 Oct 2026); latest: 11 Nov 2026
14 Trust Flow (Majestic)
first measured 25 Oct 2026
207 Referring domains (Majestic)
first measured 25 Oct 2026

Day 17 since launch. Next receipt: day 30, 24 Nov 2026. The figures report a change; they do not say what caused it, and many things can. No figure here is a guess.

Biggest gains on SaaS Directory Info

Got a launch coming up?

Step-by-step tips for before, during and after your launch, free to read on SaaS Directory Info.

Prepare
Launch day
Launch week
Next steps

Read the launch playbook

Compare and explore

Frequently looked up

Q1Does MailTester Ninja ever send an email to verify an address?: No. MailTester Ninja never sends a message. It talks to the recipient's SMTP server using commands defined by RFC 821, reads the server's answer, then stops.
Q2What does the free version of MailTester Ninja allow?: The free version verifies one email at a time with no signup required. The number of requests per minute depends on current server load and may be limited to a couple of requests per minute at peak times.
Q3Why do some email addresses return as Catch-All?: Some mail servers accept every incoming address whether the mailbox exists or not, so a specific mailbox cannot be confirmed. MailTester Ninja labels these as Catch-All instead of guessing they are valid, so you keep control.
Q4What are the API rate limits for different plans?: Pro allows 11 requests per 10 seconds (100,000 per day), Ultimate allows 23 requests per 10 seconds (200,000 per day), and a plan quantity multiplies those limits.
Q5What payment methods does MailTester Ninja accept?: Through Stripe, MailTester Ninja accepts most credit and debit cards, Apple Pay, Google Pay, Link, and Bitcoin via the Pay with crypto option.

Leave a review for MailTester Ninja

Review count for MailTester Ninja: none yet. Add the first.

Fact: reviews are free and cannot be bought. All reviews, in brief

Reviews and facts · Fact updates · Share these facts · Your SaaS? Claim this fact file · Report a wrong fact

Product	Origin	DR¹	Votes²
TempMail.nowFree temporary email address without sign-up	not stated	63	0 votes. Log in to vote for TempMail.now in the file
FutureMailEmail hosting for your own domain, built for people and their AI agents	United States	0	0 votes. Log in to vote for FutureMail in the file
5MinutesAPIWhatsApp API for OTP, alerts and bulk messaging ready in 5 minutes	Pakistan	0	0 votes. Log in to vote for 5MinutesAPI in the file
MailBenchA hosted testing SMTP inbox that captures emails without delivering them	Bangladesh	3	0 votes. Log in to vote for MailBench in the file