Welcome to the MailTester Ninja HELP page! Here you will find answers to common questions about our services, subscription management, payment methods, email verification, API usage, and more. Click on the questions to reveal the detailed answers and get the information you need quickly and efficiently.

Frequently Asked Questions

Unlimited version

How do I use my key?
Copy your key anywhere in the main form, including the curly brackets { and }. That unlocks unlimited access right away.
How many emails can I verify with the free version?
The free version verifies one email at a time. The number of requests per minute depends on current server load; at peak times it may be limited to a couple of requests per minute.
How many emails can I verify with the unlimited version?
From 100,000 emails per day up to millions, depending on your plan. There is no cap on the total number of emails you can verify over time with the email verifier.
I subscribed but can't verify more than a few emails?
Make sure your subscription is active and that your key is entered in the main form. You need to enter the key again in each new browser, or after clearing your cache.
How do I verify more than 100,000 emails per day?
Pick a plan quantity at checkout to multiply your daily limit. For example, Ultimate x5 gives you 1,000,000 emails per day.
How do I create a login?
There is no account to create. We store no personal data; you get an activation key that works in any browser and can be shared. Billing and subscription are managed through our partner Stripe from the My Account menu.

Subscription management

How do I cancel a subscription?
Use the My Account menu to manage your subscription with Stripe. Older clients still on PayPal can cancel by sending a request through our contact page.
How do I pause a subscription?
Subscriptions cannot be paused. You can cancel at any time and start a new one whenever you need it.
How do I renew a subscription?
To renew a canceled subscription, subscribe again from our pricing page.
Can I buy several subscriptions at once?
Yes. Enter the different email addresses during checkout with Stripe to issue a separate key for each.
Why is my key deactivated?
A key is deactivated when the subscription is canceled and the paid cycle is over, or when a payment fails or is missing. In those cases the subscription is canceled immediately.

Payment

What payment methods are supported?
Through Stripe we accept most credit and debit cards, Apple Pay, Google Pay and Link.
Do you accept cryptocurrency?
Yes. You can pay in Bitcoin using the Pay with crypto option on the pricing page.
I can't make a payment, why?
Check with your bank, or with Stripe, that your payment method is accepted. If it still fails, reach out through our contact page.

Email verification

Does MailTester send an email to verify an address?
No. We never send a message. We talk to the recipient's SMTP server using the commands defined by the IETF in 1982 (RFC 821), read the server's answer, then stop. You can read the RFC here.
How do I filter results by verdict?
Export to CSV or copy the results straight into a spreadsheet, then filter on the verdict column. Our email verification output is made to be sorted and filtered easily.
How do I export verification results?
Use the copy or save button. Pasted into any spreadsheet, the results are laid out in columns automatically for quick analysis.
Why do some addresses come back as Catch-All?
Some mail servers accept every incoming address whether the mailbox exists or not, so a specific mailbox cannot be confirmed. We label these as Catch-All rather than guessing valid, so you keep control. More detail is on our homepage.
Why do I get different results from other tools?
Verification depth varies between providers. Some tools stop at lighter checks and report a different verdict. If a result surprises you, contact us and we will walk through it with you.

Email finder

Why do I get several possible addresses?
The finder builds likely addresses from your contact's full name, which can return more than one candidate for the same person. Finding an address assumes you know the person and have a genuine reason to reach them.
Can I use the finder to build mailing lists?
No. Building mailing lists this way is not allowed under international rules. Reaching out to a specific professional for a genuine reason is fine; mass list building is not.

API

How do I use the API?
It is a standard REST API you can call from any language. See the API guide, with copy and paste examples for cURL, Python, Node.js, PHP and more.
What are the API rate limits?
Pro allows 11 requests per 10 seconds (100,000 per day), Ultimate 23 per 10 seconds (200,000 per day), and a plan quantity multiplies that. Hammering the API with an infinite loop of simultaneous requests triggers a temporary block. Details in the API guide.
Is there an API to find addresses in bulk?
No. We do not offer bulk address finding, since lists built without the recipients' consent are not permitted.

About the company

How long has MailTester Ninja been around?
The team behind it has more than ten years of experience in email verification and deliverability.
Who builds MailTester Ninja?
MailTester Ninja is built by Unlimited & Limited, a London company, with an international team focused on fast, accurate and private email tools.