How to Find Anyone's Work Email (and Verify It Before You Send)
The reliable ways to find a professional email address in 2026 — the name-plus-domain method, email finders, lead databases — and how to verify an email so your campaign never bounces.
The acquiresure team · · updated · 6 min read
Key takeaways
- Combine first name, last name and company domain, and let an email finder check the address against the company's mail server.
- Pattern-guessing works sometimes, but every unverified guess risks a hard bounce that hurts your sender reputation.
- Verify before sending — valid means send, risky (catch-all) means be careful, invalid means never send.
- On acquiresure, a found email costs 1 credit (about $0.0125) and a verification 0.1; no result means no charge.
The most reliable way to find someone's work email is to combine their first name, last name and company domain, then let an email finder check the address against the company's mail server before returning it. Guessing patterns works occasionally, but a verified finder is the only method that scales and doesn't poison your sender reputation with bounces.
This guide walks through every method that still works in 2026, from free pattern-guessing to agent-driven lookup, and explains how to verify what you find before a single email goes out.
What's the fastest way to find a work email address?
Take the person's name and their company's domain, and run them through an email finder. A good finder tests candidate addresses against the company's mail servers and returns one it has confirmed is deliverable, so you start with an address that actually receives mail.
With acquiresure, finding one work email costs 1 credit, and if no email exists you pay nothing — which is the honest way to price a lookup, because guessing is exactly what you're paying to avoid.
Method 1: Guess the pattern and check it yourself
Most companies use one of a handful of patterns for everyone:
first@company.com— very common in small companies and startupsfirst.last@company.com— the default at most mid-size companiesf.last@company.comorfirstinitiallast@company.com— common in large, older organisationsfirst_last@company.com— frequent in engineering-heavy companies
If you know one address at a company — say, the one on a press release or a job posting — you already know the pattern, and one guess for a new person is often right.
The problem: you can't know an unverified guess is deliverable. Sending to a mailbox that doesn't exist produces a hard bounce, and every bounce damages your sender reputation. If you must guess, verify first (see below).
Method 2: Use an email finder API
An email finder does the guessing and the checking for you. You send a first name, last name and company domain; the service generates the likely candidates, checks them against the mail server, and returns the one that works — sometimes with the source that corroborates it.
A REST call looks like this:
POST /v1/email/find
{ "firstName": "Maya", "lastName": "Chen", "domain": "brightpathfin.com" }
The response contains the email, a confidence score and how the address was found. If the finder can't produce a deliverable address, a good API returns nothing — and doesn't charge you for the miss. That's how acquiresure's email finder works: 1 credit per email found, free when nothing is found.
Method 3: Start from the role, not the name
Often you don't have a name — you have a target: "the Head of Sales at Series A fintechs in New York." Then the order of operations flips:
- Search a lead database by title, skills, location and company filters. Counting the matches costs nothing on acquiresure; listing them costs 0.1 credits per lead.
- Pick the right person, not just any person — the one whose job makes your email relevant.
- Reveal their email from the profile (1 credit, charged only when an email is actually found).
This is the workflow AI agents run best: you brief them on who you want to reach, and they search, filter and fetch verified emails in one pass.
Why you must verify an email before sending
Every hard bounce tells the receiving server you send to addresses you never checked. Accumulate enough of them and your messages start landing in spam — for everyone, not just the address that bounced. Verification is how you protect the reputation of the domain you send from. Mailbox providers are strict about this: Gmail's sender guidelines require bulk senders to authenticate with SPF, DKIM and DMARC and to keep their reported spam rate below 0.3%.
A verification service connects to the recipient's mail server and performs a handshake: it asks whether the mailbox exists and accepts mail, without actually sending a message. In SMTP terms (RFC 5321) that's the RCPT TO step, where a 550 reply means the mailbox is unavailable. From that handshake (plus DNS checks on MX records and catch-all behaviour) you get a verdict:
- Valid — the mailbox exists and accepts mail. Send with confidence.
- Risky — the domain is a catch-all (it accepts everything, so existence can't be confirmed) or the server gave an ambiguous answer. Send carefully, or not at all.
- Invalid — the mailbox doesn't exist. Never send.
On acquiresure, verification costs 0.1 credits and risky results are never charged — you only pay for the answer you can act on. Batch verification handles up to 100 emails per run, and duplicates cost nothing.
How to do all of this from your AI agent
If Claude, Cursor, Codex or another MCP-speaking agent does your prospecting, you don't call the API — your agent does. Paste one prompt:
Install the acquiresure MCP server by following https://api.acquiresure.cloud/mcpinstall.md. My API key is
.
Then brief it like a teammate: "Find 20 heads of growth at Series A SaaS companies in New York and get me their verified work emails." The agent searches the lead database, reveals the emails, verifies each one and hands you a list that won't bounce. Start with 10 free credits — no card needed.
Frequently asked questions
Is it legal to email someone's work address?
B2B outreach to professional email addresses is legal in most countries when the message is relevant to the person's job and includes an easy way to opt out. Some regions, including parts of the EU, have stricter rules — check the rules where your prospects are, and don't spam.
How accurate are email finders?
A finder that verifies against the mail server before returning an address is materially more reliable than pattern-guessing, because it reports what the server said rather than what a pattern predicts. Look for a verdict and a confidence score with every result, and never trust a finder that claims 100% accuracy.
What is a catch-all domain?
A catch-all domain accepts mail for every address at the company, including ones that don't exist. That means a server handshake can't confirm an individual mailbox, so any address at a catch-all domain is inherently risky. acquiresure flags catch-alls in every verification and never charges for a risky result.
Can I verify a whole list at once?
Yes. Batch verification checks up to 100 emails per run in the background, deduplicates for free, and refunds risky and unprocessed emails. Give the list to your agent and ask it to "verify this CSV and drop anything that would bounce."
How much does it cost to find and verify one email?
Finding a work email costs 1 credit (about $0.0125 on the Starter plan at $25 for 2,000 credits); verifying it costs 0.1 credits. If no email is found or the verification comes back risky, you pay nothing. New accounts get 10 free credits.