Email verification,
done right.

What is MailTidy3?

MailTidy3 is a self-hosted email list verification SaaS you install on your own VPS. You own the server, the data, and the throughput.

Unlike cloud-based verifiers that charge per email and throttle your throughput, MailTidy3 runs entirely on infrastructure you control. Upload a list of 100,000 emails, get accurate classifications back — valid, invalid, catch-all, disposable, role-based — without per-email fees.

The system is built on three components: a Laravel 13 web application handling auth, billing, and the buyer dashboard; a Python FastAPI verification engine doing the actual SMTP probing; and lightweight worker agents you can deploy to additional VPS to multiply throughput.

What you need.

Three non-negotiable requirements. Miss any one of them and the product will not work.

Minimum specifications

Software stack (auto-installed)

Pre-flight check

Run this on your fresh VPS before installing. If port 25 is blocked, stop and switch providers.

$ timeout 10 bash -c 'cat < /dev/tcp/gmail-smtp-in.l.google.com/25' \
  && echo "✅ Port 25 OPEN — proceed with install" \
  || echo "❌ Port 25 BLOCKED — switch VPS provider"

# You should see: 220 mx.google.com ESMTP ... then ✅

Up in under 2 minutes.

One command installs the entire stack — PHP, Python, PostgreSQL, Redis, Nginx, SSL, and the app itself.

Verifying your first list.

Three services, one purpose.

MailTidy3 splits concerns cleanly: Laravel handles the user-facing application, Python does the verification, workers scale the throughput.

Browser (React SPA)
       │  HTTPS / JSON API
       ▼
Laravel 13  (PHP 8.4)
  · Auth, billing, dashboard
  · Job state, file uploads
  · PostgreSQL 17 + Redis
       │  HTTP internal (localhost:8000)
       ▼
Python Engine  (FastAPI + asyncio)
  · Verification logic
  · Worker registry & dispatch
  · Per-domain rate limiting
  · Webhook results → Laravel
       │  HTTP (public, token-auth)
       ▼
Worker Agents  (one per VPS)
  · Polls engine for batches
  · Runs SMTP probes
  · Returns results

Why this separation?

PHP handles request/response well but can't do high-concurrency async I/O. Python (asyncio + aiosmtplib) can hold hundreds of SMTP connections in flight simultaneously. Laravel would block a PHP-FPM worker for the entire duration of a 100K-email job — Python never blocks at all.

Workers must run on separate IPs because Gmail, Yahoo, and Outlook rate-limit per source IP — not per account. Each additional worker VPS = one more independent rate-limit budget = roughly linear capacity increase.

Data flow for a verification job

Nine ways an email can be classified.

Every email gets one primary status. Role-based is a flag that can appear alongside any status.

Numbers from actual tests.

These benchmarks were run on a single Contabo VPS (2 vCPU, 3.8 GB RAM) before the MailTidy3 rebuild was committed. They are not marketing estimates.

Per-email speed

Sustained throughput (single VPS)

Soft-block wall

Gmail and other major providers rate-limit by source IP. During testing, sustained probing from a single IP hit a soft-block at approximately 4,400 emails. Recovery took 30 minutes of zero traffic. MailTidy3 handles this automatically with per-domain semaphores and auto-cooldown.

Realistic daily capacity

Any file, any structure.

MailTidy3 accepts CSV, XLSX, XLS, TSV, and TXT files up to 100 MB. Multi-column files are fully supported — the engine scans the first 100 rows to identify which column contains email addresses. If multiple columns look like emails, a column picker appears.

Accepted formats

Upload options

Verify programmatically, at scale.

MailTidy3 includes a public REST API. Generate an API key in your dashboard and start verifying from any codebase.

Authentication

All API requests require a bearer token in the Authorization header:

Authorization: Bearer mtp_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Verify a single email

POST https://app.yourdomain.com/api/v1/verify

{
  "email": "user@example.com"
}

// Response
{
  "email":        "user@example.com",
  "status":       "valid",
  "smtp_code":    250,
  "smtp_message": "2.1.5 OK",
  "mx_host":      "aspmx.l.google.com",
  "flags":        [],
  "duration_ms":  284
}

Bulk verify

POST https://app.yourdomain.com/api/v1/verify/bulk

{
  "emails": [
    "user1@example.com",
    "user2@example.com",
    "invalid@nonexistent.xyz"
  ]
}

// Response
{
  "job": {
    "id":     "job_abc123",
    "status": "processing"
  }
}

Rate limits & quotas

Verified. Now what? Push to your ESP.

When a verification job finishes, push the verified addresses straight into your email marketing platform — no CSV export, no manual import. Nine integrations are bundled, including the two self-hosted ESPs that matter most to this audience.

Supported platforms

How a push works

From the results page of any completed job, click Push to autoresponder. Pick a connected ESP, choose the target list/audience/group, decide which classifications to include (valid, catch-all, greylisted), map fields, add tags, and hit push. The job runs in the background — close the dialog and check Push History later for the per-status counts (added, updated, skipped, failed).

Mailwizz (self-hosted)

If you already run Mailwizz on your own server, this is the most direct integration — your verified contacts go straight into the same database your campaigns send from.

Step 1 — Find your Mailwizz API URL
It's your Mailwizz install plus /api, e.g. https://mail.yourdomain.com/api.

Step 2 — Generate a public API key
In Mailwizz Customer Area, go to API Keys → Create new. Copy the public key — Mailwizz uses public/private key signing, so the public key is what MailTidy3 needs.

Step 3 — Get the list UID
Go to Lists, open the target list, and look at the URL. The UID is the alphanumeric segment after /lists/. You'll need it when pushing.

Step 4 — Connect in MailTidy3
Go to Settings → Integrations → Mailwizz → Connect. Paste the API URL and public key. Click Test connection. On success, the list selector populates automatically — no need to copy the UID manually.

Acelle Mail (self-hosted)

The other major self-hosted ESP. Same direct database push, same workflow.

Step 1 — Find your Acelle API URL
Your install plus /api/v1, e.g. https://acelle.yourdomain.com/api/v1.

Step 2 — Generate an API token
In Acelle, go to Profile → API Token → Generate. Copy the token.

Step 3 — Connect in MailTidy3
Settings → Integrations → Acelle → Connect. Paste API URL and token. Test connection — your lists appear in the dropdown.

Mailchimp

Step 1 — Generate an API key
In Mailchimp, click your profile (top right) → Profile → Extras → API keys → Create A Key. The key looks like a1b2c3d4e5f6g7h8-us21. The suffix after the dash (us21) is your data centre — Mailchimp embeds it in the key itself.

Step 2 — Find your Audience ID
Go to Audience → All contacts → Settings → Audience name and defaults. The Audience ID is shown near the bottom — it's a 10-character alphanumeric string.

Step 3 — Connect
Settings → Integrations → Mailchimp → Connect. Paste the API key. Audiences populate automatically. Map fields like FNAME, LNAME, or any merge field you've added. Tags can be auto-applied (e.g. mailtidy-verified).

Brevo (formerly Sendinblue)

Step 1 — Generate an API key
In Brevo, click your account (top right) → SMTP & API → API Keys → Generate a new API key. Give it a name like "MailTidy 3" and copy the key (starts with xkeysib-).

Step 2 — Connect
Settings → Integrations → Brevo → Connect. Paste the API key. Lists load from your account. Optionally set default tags, then save.

Kit (formerly ConvertKit)

Step 1 — Get your API credentials
In Kit, go to Settings → Advanced → API. You need both the API Key (for general calls) and API Secret (for adding subscribers).

Step 2 — Connect
Settings → Integrations → Kit → Connect. Paste both keys. Kit organises subscribers around Forms and Sequences — pick which to push to. Tags can be applied to all pushed subscribers.

GetResponse

Step 1 — Generate an API key
In GetResponse, go to Menu (top left) → Integrations and API → API → Generate API key. Give it a label and copy the key.

Step 2 — Connect
Settings → Integrations → GetResponse → Connect. Paste the API key. Your campaigns (lists) populate automatically. Map custom fields, set tags, save.

ActiveCampaign

Step 1 — Get API URL and Key
In ActiveCampaign, go to Settings → Developer. You'll see your API URL (looks like https://youraccount.api-us1.com) and Key. Copy both.

Step 2 — Connect
Settings → Integrations → ActiveCampaign → Connect. Paste both values. Lists load. Map ActiveCampaign custom fields to MailTidy3 data, set tags, save.

Campaign Monitor

Step 1 — Get your API key
In Campaign Monitor, click your account name (top right) → Account Settings → API keys → Show API key. Copy it.

Step 2 — Find your Client ID
From the same Account Settings page, your Client ID is shown — it's a long alphanumeric string. You'll need it to identify the right account when multiple clients exist under one login.

Step 3 — Connect
Settings → Integrations → Campaign Monitor → Connect. Paste API key and Client ID. Lists load.

MailerLite

Step 1 — Generate an API token
In MailerLite, go to Integrations → API → Generate new token. Give it a name and copy the token. Note: MailerLite has both Classic and the new platform — make sure you're generating the token from the version you actually use.

Step 2 — Connect
Settings → Integrations → MailerLite → Connect. Paste the token. Groups populate (MailerLite uses Groups instead of Lists). Map custom fields, set tags, save.

Push options reference

For SaaS operators (Extended License)

If you run MailTidy3 as a SaaS for your own paying customers, the SaaS Admin includes a separate flow: SaaS Admin → Customer Lists → Push to autoresponder. This pushes your customer accounts (with consent) to your own marketing autoresponder — useful for product announcements, upgrade nudges, and onboarding sequences targeted at the people paying you.

Add a worker, double the throughput.

Each worker VPS runs a single Python agent that polls the engine for email batches. Workers on different IPs have independent rate-limit budgets with Gmail, Yahoo, and Outlook.

When to add workers

The main VPS handles ~150,000 emails/day comfortably. Add workers if you regularly process lists over 100,000 emails, run multiple client lists simultaneously, or need guaranteed same-day turnaround on large batches.

Adding a worker — 3 steps

$ curl -fsSL https://install.mailtidypro.com/worker | bash -s \
  YOUR_TOKEN_HERE \
  https://app.yourdomain.com

Full control, one place.

The admin panel is available to accounts with the admin role. The Extended License additionally unlocks the SaaS Admin section for running MailTidy3 as a multi-tenant service.

Admin capabilities

Extended license (SaaS Admin)

Sending emails from your install.

MailTidy3 sends emails for: account verification, password reset, and job completion notifications. These go through the SMTP settings you configure in the admin panel.

Recommended providers

Settings

Regular vs Extended.

How to activate

Go to Settings → Envato License. Select your license type, paste your Envato purchase code, and click Activate. The purchase code is in your Envato account under Downloads → License certificate & purchase code.

Where to host.

Maximum deliverability.
Best results, stay unblocked.

MailTidy3 is already built with anti-block mechanisms baked in — per-domain semaphores, automatic soft-block detection, 30-minute IP cooldowns, and multi-worker routing. But there are five additional steps you should complete on every VPS you install, including workers. They take under an hour total and the difference in accuracy is significant.

Step 1 — Set reverse DNS (PTR record) Most important

When your VPS connects to Gmail's mail server, Gmail does a reverse DNS lookup on your IP. If the IP doesn't resolve back to a proper hostname, Gmail silently downgrades or rejects the conversation. This is the single most common cause of unknown results on a fresh install.

You need one PTR record per VPS — set from the Contabo control panel, not from DNS. DNS A records alone are not enough.

What to set

How to set it on Contabo

# Verify PTR (reverse DNS) — replace with your actual IP
$ dig -x YOUR_VPS_IP +short
mail.yourdomain.com.   # ✅ correct
vmi123456.contaboserver.net.  # ❌ not set yet — wait longer or re-check Contabo panel

# Verify the forward lookup matches (FCrDNS check)
$ dig mail.yourdomain.com +short
YOUR_VPS_IP  # ✅ must match the IP above

Step 2 — Add your VPS IPs to SPF

SPF (Sender Policy Framework) tells receiving mail servers which IPs are authorised to send mail from your domain. The engine sends MAIL FROM: verify@yourdomain.com during every probe. Without your VPS IPs in the SPF record, the probe gets a softfail (~all) which some providers treat as suspicious.

Go to your DNS provider (Cloudflare, Namecheap, etc.) and find the TXT record for your domain. Edit the existing SPF record — do not add a second one, two SPF records on the same domain breaks SPF entirely.

# If you have Google Workspace email (support@yourdomain.com):
v=spf1 include:_spf.google.com ip4:MAIN_VPS_IP ip4:WORKER_1_IP ip4:WORKER_2_IP ~all

# If you don't use Google Workspace:
v=spf1 ip4:MAIN_VPS_IP ip4:WORKER_1_IP ~all

# Add each worker IP as a new ip4: entry when you add workers

# Verify SPF propagated (takes 1–5 minutes on Cloudflare)
$ dig TXT yourdomain.com +short | grep spf
"v=spf1 include:_spf.google.com ip4:84.46.245.142 ~all"  # ✅

Step 3 — Set the correct HELO hostname per worker

During every SMTP probe, the engine introduces itself with an EHLO command: "Hello, I am mail.yourdomain.com." The receiving server cross-checks this hostname against the connecting IP. A mismatch — or a generic Contabo hostname like vmi123456.contaboserver.net — causes Gmail to treat the connection as suspicious.

Each worker should EHLO with its own dedicated hostname that has a matching A record and PTR.

# Main VPS — edit /opt/mailtidy-engine/.env
SMTP_HELO_DOMAIN=mail.yourdomain.com
SMTP_MAIL_FROM=verify@yourdomain.com

# Worker VPS — edit /opt/mailtidy-worker/.env
MAILTIDY_HOSTNAME=mail2.yourdomain.com

# After editing, restart the relevant service

# On main VPS:
$ sudo systemctl restart mailtidy-engine

# On worker VPS:
$ sudo systemctl restart mailtidy-worker

Step 4 — Check your IP is not already blacklisted

If your VPS IP is listed on Spamhaus SBL, CBL, or similar RBLs, every single probe will be rejected before it even gets a real response. This is the first thing to check when you see 100% unknown results on a fresh install.

Run this on each VPS immediately after provisioning, before installing anything:

# Get your public IP
$ curl -s ifconfig.me
84.46.245.142

# Check Spamhaus — reverse the IP octets before the lookup
# For IP 84.46.245.142 → check 142.245.46.84.zen.spamhaus.org
$ dig +short 142.245.46.84.zen.spamhaus.org
# No output = not listed ✅
# 127.0.0.2 or similar = listed ❌

# Easy web alternative: https://mxtoolbox.com/blacklists.aspx

Step 5 — Understand the rate limits and work with them

MailTidy3's engine already enforces per-domain concurrency limits and automatic cooldowns. Understanding how the limits work helps you get the most out of each IP without triggering blocks.

The engine detects soft-blocks automatically — when error rate exceeds 80% for a provider on a given IP, that IP is put into a 30-minute cooldown for that provider only, and remaining emails are routed to other healthy worker IPs. You can monitor this in real time on the Workers → IP Health panel in your admin dashboard.

Quick checklist — do this for every VPS

Run through this for your main VPS and every worker you add. The whole process takes about 20 minutes per VPS (mostly waiting for PTR propagation).

End-to-end test after setup

After completing all five steps, test with a known-valid email address using your API key. A correct result looks like this:

$ curl -s \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"email":"known-valid@gmail.com"}' \
  https://app.yourdomain.com/api/v1/verify | python3 -m json.tool

✅ Correct result — everything is configured properly:
{
  "email":        "known-valid@gmail.com",
  "status":       "valid",
  "smtp_code":    250,
  "smtp_message": "2.1.5 OK ...",
  "mx_host":      "aspmx.l.google.com",
  "duration_ms":  312.4    ← under 1 second = healthy connection
}

❌ Problem result — PTR/HELO misconfigured or IP blocked:
{
  "status":      "unknown",
  "smtp_code":   null,
  "error":       "timeout",
  "duration_ms": 10014.6   ← 10 seconds = connection never completed
}

When things go wrong.

All verifications return UNKNOWN

Results table shows "No results match this filter"

Job stuck at 0% / never starts

Ghost workers in the workers panel

Log locations

# Engine logs
$ sudo tail -f /var/log/mailtidy-engine/engine.log

# Worker logs
$ sudo tail -f /var/log/mailtidy-engine/worker.log

# Laravel logs
$ sudo tail -f /var/www/mailtidy/storage/logs/laravel.log

# Nginx logs
$ sudo tail -f /var/log/nginx/error.log

Why Gmail says unknown.

You install MailTidy3, run your first verification, and Yahoo addresses come back in 1.5 seconds — clean, accurate, perfect. But every Gmail address times out at 10 seconds and returns unknown. Nothing is broken. This is Gmail deliberately ignoring you, and there is a precise fix.

What actually happens under the hood

When MailTidy3 verifies an email address, it connects to the recipient's mail server on port 25 and has a short SMTP conversation — no actual email is ever sent. Gmail's MX servers (gmail-smtp-in.l.google.com) accept the TCP connection from your IP, but before responding they do a reverse DNS lookup (PTR record) on your IP address.

What they find on a fresh Contabo VPS is something like vmi1478013.contaboserver.net — a generic hostname that millions of spam servers also have. Gmail's response: silently hold the connection open for 10 seconds, then drop it. Your verification returns unknown. This is not a bug. It is Gmail protecting its users from probes it cannot verify.

How to diagnose it

First, confirm the problem is rDNS and not a soft-block. Run these two tests back-to-back on your VPS:

# Test 1 — Does Yahoo work fast? (it should)
$ curl -s -w "\nTime: %{time_total}s\n" https://app.yourdomain.com/api/v1/verify \
  -X POST \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"email":"test@yahoo.com"}'
# Expect: status "valid" or "catch_all" in ~1-2 seconds

# Test 2 — Does Gmail time out?
$ curl -s -w "\nTime: %{time_total}s\n" https://app.yourdomain.com/api/v1/verify \
  -X POST \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"email":"someone@gmail.com"}'
# If this takes 10 seconds and returns "unknown" — it's rDNS.

# Check your current PTR record
$ dig -x YOUR_VPS_IP +short
# Bad:  vmi1478013.contaboserver.net.
# Good: mail.yourdomain.com.

The fix — 2 steps, 5 minutes

Verify it worked

PTR propagation typically takes 30–60 minutes. Run this to check:

# Both commands should reference each other
$ dig -x 84.46.245.142 +short
mail.mailtidypro.com.   # ← should return your domain, not contaboserver.net

$ dig mail.mailtidypro.com A +short
84.46.245.142           # ← should return your IP

Once both match, test Gmail verification directly:

$ curl -s -w "\nTime: %{time_total}s\n" https://app.yourdomain.com/api/v1/verify \
  -X POST \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"email":"someone@gmail.com"}'
# After fix: status "valid" or "invalid" in under 2 seconds.
# Before fix: status "unknown" after exactly 10 seconds.

Six tools, built in.

Email deliverability lives or dies on DNS. MailTidy3 ships six diagnostic tools that let you check the records that matter — without leaving the dashboard or pasting your domain into someone else's site.

Open Diagnostics → Tools in the sidebar. Every user (including demo accounts) can run them; results are cached for six hours per (domain or IP, tool) pair so repeated checks are instant. All six are also exposed as API endpoints for Extended License holders.

The six tools

Input persistence between tools

Type a domain into the SPF Checker, then jump to the DMARC or DKIM Checker via the switcher strip — the domain is already filled in. Same for IP-based tools (rDNS and Blacklist share the IP field). It's stored in sessionStorage, so it clears when you close the tab.

Tool API (Extended License)

Each tool is also a REST endpoint. Useful if you want to surface the results inside another product or run scheduled checks on your own infrastructure.

Authentication — the tool API uses the same bearer-token scheme as /api/v1/verify. Generate a key in Settings → API Keys; the key must be issued under an Extended License (or by an admin) to access tool routes.

POST https://app.yourdomain.com/api/v1/tools/spf
Authorization: Bearer mtp_live_xxxxxxxxxxxxxxxx
Content-Type: application/json

{
  "domain": "example.com"
}

// Response
{
  "domain":        "example.com",
  "record":        "v=spf1 include:_spf.google.com ~all",
  "valid":         true,
  "all_mechanism": "~all",
  "includes":      ["_spf.google.com"],
  "warnings":      [],
  "checked_at":    "2026-05-05T12:34:56Z"
}

All tool endpoints

Rate limits

Accept payments. Your gateway, your money.

MailTidy3 supports five payment gateways. Each is off by default — you enable only the one(s) you want. All configuration is done through the admin panel; no `.env` editing is needed after install.

Go to Admin → Settings → Payment Gateways to configure any gateway. Changes take effect immediately — no server restart required.

Stripe

Stripe is the recommended gateway for most installs. It supports subscriptions, one-time payments, and automatic invoicing in 135+ currencies.

Step 1 — Create a Stripe account
Go to stripe.com and sign up. Complete identity verification before going live.

Step 2 — Get your API keys
In the Stripe Dashboard go to Developers → API keys. Copy your Publishable key (pk_live_...) and Secret key (sk_live_...). Use test keys (pk_test_... / sk_test_...) while testing.

Step 3 — Create your products
In Stripe Dashboard go to Product catalogue → Add product. Create one product per plan that matches what you've set up in Admin → Pricing. For each product, set a recurring price (monthly or yearly). Copy the Price ID (price_xxx) — you'll need it in the next step.

Step 4 — Enter credentials in MailTidy3
Go to Admin → Settings → Payment Gateways → Stripe. Enter your Publishable key, Secret key, and the Price IDs for each plan. Toggle Enable Stripe on. Click Save.

Step 5 — Set up the webhook
In Stripe Dashboard go to Developers → Webhooks → Add endpoint. Set the endpoint URL to:

https://app.yourdomain.com/api/billing/stripe/webhook

Select these events: customer.subscription.created, customer.subscription.updated, customer.subscription.deleted, invoice.payment_succeeded, invoice.payment_failed.
Copy the Webhook signing secret (whsec_...) and paste it into Admin → Settings → Payment Gateways → Stripe → Webhook Secret.

Step 6 — Test it
Use Stripe's test card 4242 4242 4242 4242 (any future expiry, any CVC) to complete a test purchase. Confirm the subscription appears in Admin → Billing.

Paddle

Paddle acts as the merchant of record — they handle VAT, GST, and sales tax on your behalf. Ideal if you sell globally and don't want to deal with tax compliance yourself.

Step 1 — Create a Paddle account
Go to paddle.com. Paddle requires business verification before you can go live — allow 1–3 business days.

Step 2 — Get your API credentials
In the Paddle Dashboard go to Developer Tools → Authentication. Copy your Vendor ID and generate an API key. Also note your Client-side token for the frontend.

Step 3 — Create your plans in Paddle
Go to Catalog → Products. Create a product for each plan. Under each product, create a Price (recurring). Copy the Price ID for each.

Step 4 — Enter credentials in MailTidy3
Go to Admin → Settings → Payment Gateways → Paddle. Enter your Vendor ID, API key, Client-side token, and Price IDs. Toggle Enable Paddle on. Click Save.

Step 5 — Set up the webhook
In Paddle Dashboard go to Developer Tools → Notifications → New destination. Set URL to:

https://app.yourdomain.com/api/billing/paddle/webhook

Select all subscription and payment events. Copy the secret key Paddle generates and enter it in Admin → Settings → Payment Gateways → Paddle → Webhook Secret.

Razorpay (India)

Razorpay is the most popular payment gateway for India, supporting UPI, NetBanking, cards, and wallets in INR.

Step 1 — Create a Razorpay account
Go to razorpay.com. Complete KYC verification. You can use test mode immediately without KYC.

Step 2 — Get API keys
In the Razorpay Dashboard go to Settings → API Keys → Generate Test Key (or Live Key). Copy the Key ID (rzp_live_...) and Key Secret.

Step 3 — Create plans in Razorpay
Go to Subscriptions → Plans → Create plan. Create one plan per pricing tier. Copy the Plan ID (plan_...) for each.

Step 4 — Enter credentials in MailTidy3
Go to Admin → Settings → Payment Gateways → Razorpay. Enter your Key ID, Key Secret, and Plan IDs. Toggle Enable Razorpay on. Click Save.

Step 5 — Set up the webhook
In Razorpay Dashboard go to Settings → Webhooks → Add new webhook. Set URL to:

https://app.yourdomain.com/api/billing/razorpay/webhook

Select events: subscription.activated, subscription.charged, subscription.cancelled, payment.captured, payment.failed.
Enter a Webhook Secret of your choice and paste the same value in Admin → Settings → Payment Gateways → Razorpay → Webhook Secret.

Paystack (Africa)

Paystack is the leading gateway for Nigeria, Ghana, Kenya, and South Africa. Supports cards, bank transfers, and mobile money.

Step 1 — Create a Paystack account
Go to paystack.com. Business registration required for live mode.

Step 2 — Get API keys
In the Paystack Dashboard go to Settings → API Keys & Webhooks. Copy your Public Key (pk_live_...) and Secret Key (sk_live_...).

Step 3 — Create plans
Go to Products → Plans → Create Plan. Create one plan per pricing tier. Copy the Plan Code for each.

Step 4 — Enter credentials in MailTidy3
Go to Admin → Settings → Payment Gateways → Paystack. Enter your Public Key, Secret Key, and Plan Codes. Toggle Enable Paystack on. Click Save.

Step 5 — Set up the webhook
In Paystack Dashboard go to Settings → API Keys & Webhooks → Webhook URL. Set it to:

https://app.yourdomain.com/api/billing/paystack/webhook

Paystack signs all webhooks with your Secret Key — no separate webhook secret needed.

Flutterwave (Africa)

Flutterwave operates in 30+ African countries and supports cards, bank transfers, mobile money, and USSD.

Step 1 — Create a Flutterwave account
Go to flutterwave.com. Complete business verification for live mode.

Step 2 — Get API keys
In the Flutterwave Dashboard go to Settings → API → API Keys. Copy your Public Key, Secret Key, and Encryption Key.

Step 3 — Create payment plans
Go to Payment Plans → Create a plan. Create one plan per pricing tier. Copy the Plan ID for each.

Step 4 — Enter credentials in MailTidy3
Go to Admin → Settings → Payment Gateways → Flutterwave. Enter your Public Key, Secret Key, Encryption Key, and Plan IDs. Toggle Enable Flutterwave on. Click Save.

Step 5 — Set up the webhook
In Flutterwave Dashboard go to Settings → Webhooks. Set URL to:

https://app.yourdomain.com/api/billing/flutterwave/webhook

Generate a Secret Hash in the Flutterwave webhook settings and enter the same value in Admin → Settings → Payment Gateways → Flutterwave → Webhook Secret.

Common questions.

Does MailTidy3 send actual emails?

No. The verification engine connects to recipient mail servers, introduces itself (EHLO), and asks whether a mailbox exists (RCPT TO) — then disconnects before sending anything. No email is ever delivered.

Will my IP get blacklisted?

MailTidy3 uses per-domain rate limiting (max 5 concurrent probes per recipient domain) and automatic cooldown when error rates spike. During testing, 4,400+ emails through a single IP triggered a temporary Gmail soft-block — which cleared in 30 minutes. The system detects this automatically.

Can I white-label this for my customers?

Yes, with the Extended License. Install MailTidy3 on your own VPS, customize branding through the admin panel, point your domain at it, and sell verification credits to your customers.

What's the difference between Regular and Extended license?

Regular is for using MailTidy3 for your own email verification needs. Extended allows you to run it as a SaaS — charging your own customers for verification. See the license comparison table above.

How accurate is it?

In pre-launch testing across ~500 hand-verified results, classification was correct in every case. Catch-all detection was a major improvement over the original MailTidy — the new probe sends a random address before classifying as "valid".

Does it work with Outlook/Hotmail?

Microsoft's mail servers are conservative and don't always return definitive accept/reject responses for unrecognised source IPs. Results for @outlook.com and @hotmail.com will often come back as "unknown". This is a limitation of Microsoft's SMTP behaviour, not a bug.

Can I run it on 1 GB RAM?

Yes — 1 GB is enough to get started and test. For production workloads, 2–4 GB is recommended. The Python engine and Redis together use roughly 400–600 MB at rest.

Is there a hosted version?

Not currently. MailTidy3 is self-hosted only — you own the server and the data. A hosted cloud edition is on the roadmap.