Company email format finder: the pattern a domain uses, so a name becomes an address

What 100 of these actually costs

Subscription figures are provider list prices recorded in treg.to’s own catalog grid; per-call prices are what treg.to charges today, with $0.000 added.

What’s the best way to ask ChatGPT?

set up treg — https://treg.to/llms.txt

Using treg, get the email format for these 40 company domains, show me the price per domain for each provider first, then give me a table of domain, pattern, confidence and which provider answered, and leave the pattern blank where nothing came back rather than guessing first.last.

works in

Why this prompt works

Why go through treg.to

What ChatGPT sees before it calls

treg.to does not choose for you. It hands ChatGPT this comparison, with the price shown before any call, and ChatGPT picks. Or you tell it how: "cheapest", "most reliable", "the one that takes what I have", or a provider by name.

Which email format finder is cheapest?

Those units are not interchangeable: one call can return many results, so compare on the unit you will actually be billed in.

How do the two compare?

Provider	Price	Accepts	Success rate	Verified
▚The Companies API	$0.0019 per found	emailsCount, precision, domain	not yet measured	unverified
Tomba	$0.0089 per call	domain	not yet measured	2026-08-20

Run one

treg call thecompaniesapi.companies.email_pattern

Swap the id for any provider above. All 2 endpoints behind this job, with their parameters and captured responses, are on the Company data shelf.

How these numbers are made

What people actually struggle with

This is a thin corpus honestly reported: of the ~180 Reddit and X posts read in August 2026 about twenty were on the job, and nine vendor clusters, one in bold Unicode from two accounts, were excluded. Nobody complains about the pattern step itself; they complain about what happens after it.

The pattern is easy, which cuts both ways

“My work email follows a predictable format, so I surmise it's not hard to guess from my name.” r/recruitinghell, 2,112 points

What this page can do about it: That predictability is the whole reason a pattern call works, and it is why the call is cheap: most companies follow one rule. The page will not pretend the hard part is here; the hard part is knowing whether the person still has the mailbox.

The price of the tools, or the price of your evening

“You either pay thousands for tools like ZoomInfo/Apollo or you spend hours manually scraping LinkedIn and hoping a generic email format works.” r/smallbusiness

What this page can do about it: Neither, is the honest answer. A pattern lookup is a fraction of a cent per domain, billed from a prepaid balance with no seat and no contract, and the agent can chain it to a verify call so the guess is checked before it is sent.

Everyone is guessing from the same data

“Out of 100 people I actually wanted, maybe one address worth sending to.” X

What this page can do about it: A pattern will not raise that number on its own. What it changes is the cost of trying: a probable address for everyone on the list for cents, then verification to keep the ones that exist. The list itself is still your job.

Fatigue with the usual databases

“I'm increasingly skeptical of relying only on Apollo, Hunter and the usual databases. Everyone is targeting the same people with the same data.” X, 6 likes

What this page can do about it: A pattern call is not a database of people. It gives you the rule, and you bring the names, which means the addresses you build are for the people you chose rather than the ones every other list already carries.

Finding the person is the bottleneck, not the address

“Scraping Google Maps is easy. Finding the real owner behind each business is the bottleneck.” X, 3 likes

What this page can do about it: Agreed, and this page does not solve it. Once you have a name and a domain, the pattern makes the address a one line step; the people search and enrichment pages are where the name comes from.

What actually differs

The two rows bill in different units, so the cheapest depends on your hit rate.

The Companies API is priced per pattern found, so a domain with no known addresses costs nothing; Tomba is priced per call, and its logs showed the first call of the day at one credit and two replays of the same domain at zero, so a repeat inside the month is free. On a list of well known domains the per call row is the cheaper one; on a list of small companies the per found row is. Both are the provider's own rate with $0.000 added.

A pattern is only as good as the sample behind it.

Both providers infer the format from addresses they have seen on the domain, and a domain with three known addresses yields a confident looking pattern that may be wrong for the fourth person. Read the confidence or count the provider returns, and treat anything built on a handful of samples as a hypothesis to verify, not a fact to send to.

Tomba's row has been called live through treg.

to and carries a verified date; The Companies API row is documented but not yet verified through treg.to, so run one domain before an agent runs a thousand. The 1,300 a month who search for an email format checker are mostly asking whether an address is valid, which is a different call: that is the verify page, and the two calls are meant to run one after the other.

What is a company email format finder?

It is a call that takes a domain and returns the shape of that company's addresses, learned from addresses already seen on that domain: first.last@, first@, flast@, first_last@ and so on, usually with a count or a confidence behind each. With the pattern and a person's name, an agent can write a probable address for anyone at the company without a per person lookup. It is the cheap first step in an outreach pipeline, and only the first step: a probable address still bounces if the person has left, uses a middle initial or is the one exception, which is why the pattern call is normally followed by a verify call on the address it produced.

Before you start

Does the pattern give me a working address?

No. It gives you the rule the company follows, and the address you build from it is probable, not confirmed. Verify it before sending: a bounce from a guessed address costs more in sender reputation than the verify call costs in cents.

Which is cheaper, per pattern or per call?

It depends on how many of your domains have a known pattern. The Companies API charges only when it finds one, Tomba charges the call and makes repeats free within the month. Ask the agent to print both rates against your list before it runs.

Can I get the pattern from a company name instead of a domain?

Not in one step. Resolve the name to a domain first, which Tomba's suggestions row does for a credit, then ask for the pattern. An agent can chain the two.

Is guessing addresses from a pattern allowed?

A pattern is public information about how a company names mailboxes, and building an address from it is what every outreach tool does. What you then send, to whom and under which rules is your responsibility, and nothing here changes that.

Other jobs your agent can do