Bulk Email Verifier - SMTP Validation & Deliverability Check

What is Bulk Email Verifier?

Bulk Email Verifier checks whether an email address can actually receive mail, and it does it at the SMTP level — not with a regex, and not with a lookup table.

For every address it resolves the domain's MX records, opens a connection to the mail server and issues a real RCPT TO probe. That is the same step a mail server performs right before it accepts a message, which is why it is the only check that can tell you a mailbox truly exists.

Two extra guards make the verdict trustworthy:

• Catch-all detection. Many domains accept every address and bounce later. The Actor probes the domain with a random 20-character local part as a control. If the control address is accepted too, the domain is flagged accept_all and you are told the mailbox was not confirmed.
• Disposable detection. An 8,870-domain blocklist built from three public sources catches throwaway addresses before any network probe is made.

You get a verdict per row (safeToSend is the single field most users branch on), and you only pay for rows that carry a verdict. Anything the Actor could not decide comes back as unknown and is free.

What can this Actor do?

• ✅ Mailbox-level confirmation via syntax + MX + SMTP RCPT TO
• ✅ Catch-all / accept-all detection with a random-address control probe
• ✅ Disposable and role account (sales@, support@, …) detection
• ✅ Large-provider fallback — Gmail, Outlook, Yahoo, iCloud, Proton, Zoho, Fastmail, Yandex, QQ and 163 block probing on purpose. Instead of returning a useless unknown, the Actor returns a provider-level verdict at half the price of a mailbox-confirmed check
• ✅ Automatic port-25 fallback — if the container cannot reach outbound port 25, the Actor degrades to MX-only mode and bills the cheaper screening event, because no mailbox-level judgement was made
• ✅ Host-aware concurrency — per-MX-host throttling so one big provider never stalls the batch
• ✅ Built on the Apify platform: scheduling, webhooks, API access, proxy rotation and integrations are all available without extra work

How to use it

1. Open the Actor's Input tab.
2. Paste your addresses into emails, or pass a domainsCsv-style list of plain strings.
3. Leave the defaults alone for a first run — hostConcurrency 12 and a 4-second read timeout are tuned for mixed B2B lists.
4. Click Start, then download the run dataset as JSON, CSV or Excel.
5. Filter on safeToSend and keep the true rows.

A minimal input looks like this:

{
  "emails": [
    "info@apify.com",
    "this-address-does-not-exist-9182@gmail.com"
  ]
}

Pricing

This Actor is pay-per-event. You are charged per verdict produced — never per input row, and never per API call.

Event	When it is charged	Price
Email verified	A mailbox-level decision was reached	$0.99 per 1,000 ( = $0.00099 each )
Email verdict (provider-level)	Address belongs to a large provider that blocks probing	$0.50 per 1,000 ( = $0.0005 each )
Email screened (MX-only)	Container could not reach port 25, so only syntax + MX + disposable + role were checked	$0.25 per 1,000 ( = $0.00025 each )
Actor start	Once per run, per GB of memory	$0.00005 per GB

Rows that come back as unknown are never charged — if the Actor could not decide, you do not pay. Volume tiers lower the unit price automatically on Apify's BRONZE, SILVER, GOLD, PLATINUM and DIAMOND plans.

Rough budgeting, assuming every row gets a mailbox-level verdict:

Addresses in	Cost
1,000	$0.99
5,000	5 × $0.99
10,000	10 × $0.99

Real lists cost less than this ceiling, because unknown rows are free and large-provider rows bill at the lower provider rate.

Input

Field	Type	Default	Notes
emails	array	sample addresses	The addresses to verify
heloHostname	string	mailprobe.io	Hostname announced in HELO
fromAddress	string	probe@mailprobe.io	Address used in MAIL FROM
connectTimeoutMs	integer	3500	Connection timeout
readTimeoutMs	integer	4000	Read timeout for SMTP replies
hostConcurrency	integer	12	Parallel connections per MX host
dnsConcurrency	integer	12	Parallel DNS lookups
skipSmtpForDisposable	boolean	true	Skip probing known disposable domains
maxEmails	integer	50000	Safety cap per run
forceMxOnly	boolean	false	Force MX-only mode
forceSmtp	boolean	false	Force SMTP mode
providerFallback	boolean	true	Enable the large-provider heuristic

Output

One dataset item per input email:

{
  "email": "info@apify.com",
  "result": "deliverable",
  "valid": true,
  "safeToSend": true,
  "disposable": false,
  "role": false,
  "catchAll": false,
  "confidence": 100,
  "mailboxConfirmed": true,
  "smtpHost": "aspmx.l.google.com",
  "rcptToCode": 250
}

result is one of deliverable, undeliverable, accept_all, unknown, mx_only or provider_heuristic.

Other Actors you may like

• Bulk Tech Stack Detector - BuiltWith/Wappalyzer Alternative — the technologies behind a domain, with categories, versions and confidence.
• Bulk On-Page SEO Audit — 26 on-page checks and a 0–100 score.
• ATS Job Board Feed Sync - Greenhouse, Lever, Ashby — normalize career pages across every major ATS.

FAQ

Why not just use a regex? A regex only tells you the address is shaped like an address. Only an SMTP probe tells you the receiving server would accept it.

What is a catch-all and why does it matter? A catch-all domain answers "yes" to every address. Any verifier that reports those as valid will hand you a list full of addresses that bounce. This Actor flags them as accept_all with mailboxConfirmed: false.

Will you probe Gmail? Gmail and other large providers deliberately block RCPT TO probing. We do not fake a result — you get a provider-level verdict at roughly half price, clearly marked so you can decide.

Does a failed run cost me anything? No. Billing is per event, and events are only emitted when a verdict is written.