> Enrich.chat gives AI agents verified work emails and mobiles. To use it from an agent, read https://enrich.chat/agents.md . This is the Markdown version of https://enrich.chat/tools/email-format-finder/

> **Note for agents:** this tool is a web form that people use in a browser, so you cannot submit it. Use the Enrich.chat API instead, as described in https://enrich.chat/agents.md .

# Free email format finder: look up any company's email pattern

Enter a company website to see how it builds staff addresses, such as first.last@, with an example, the other formats in use, and whether the domain accepts all mail.

By Enrich.chat Editorial. Updated October 15, 2026.

## What you get

- The most common format at the domain, with an example address
- Other formats seen at the same domain
- Whether the domain is catch-all, so you know if an address can be verified

Each check uses 1 of your 10 free lookups, shared across Enrich.chat's free tools. A domain with no match does not use one.

**Short answer:** A company email format is the rule a company uses to build staff addresses from names, such as first.last@acme.com. Admins usually set it once, for example as an [Exchange address template](https://learn.microsoft.com/en-us/exchange/email-addresses-and-address-books/email-address-policies/email-address-policies), so one real address usually reveals the rest. This free email format finder takes a domain and shows the most common format, an example, other formats seen, and whether the domain is catch-all.

## Key takeaways

- A format finder matches known addresses at a domain to people's names, counts the patterns, and reports the most common one.
- Exceptions are normal. [UW-Stevens Point](https://help.uwsp.edu/TDClient/66/Portal/KB/Article/1679/Faculty-Staff-Email-Address-Information) adds a 2 for a second hire with the same name, and acquired brands such as [GitHub](https://github.com/about/press) keep their own domain.
- On a catch-all domain the mail server accepts every address, so no mailbox check can confirm a guess. The format is your main evidence.
- This tool shows a format, not a list of staff. [RFC 5321](https://www.rfc-editor.org/rfc/rfc5321.html#section-7.3) lets mail servers turn off EXPN, a command spammers used to harvest addresses.

## Domain in, format out

1. **Enter the company website.** Type the domain, such as acme.com. Use the domain staff send email from, which is not always the brand's website.
2. **Read the format.** You get the most common pattern, an example address, the other patterns seen there, and whether the domain is catch-all.
3. **Verify one address.** Apply the format to your contact's name, then confirm it with the [email finder](https://enrich.chat/tools/email-finder/) before you send.

## What is a company email format?

A company email format is the rule an employer uses to turn a person's name into a work address. If Jane Doe is jane.doe@acme.com, Acme's format is {first}.{last}, and her colleague Sam Lee is probably sam.lee@acme.com.

In Microsoft Exchange, the rule is an [email address template](https://learn.microsoft.com/en-us/exchange/email-addresses-and-address-books/email-address-policies/email-address-policies) built from variables: %g is the first name, %s is the last name, and %1g is the first initial. One template sets the main address for everyone the policy covers. These are the formats you will meet most often.

| Format | Jane Doe at acme.com | Exchange template |
| --- | --- | --- |
| `{first}.{last}` | jane.doe@acme.com | `%g.%s` |
| `{f}{last}` | jdoe@acme.com | `%1g%s` |
| `{first}` | jane@acme.com | `%g` |
| `{first}{l}` | janed@acme.com | `%g%1s` |
| `{last}.{first}` | doe.jane@acme.com | `%s.%g` |

Company size shapes the choice. In [Interseller's 2019 study](https://www.interseller.io/blog/2019/02/04/top-email-address-patterns-by-company-size/), first name only led at firms with up to 50 staff, and {first}.{last} led above 1,000. The [email permutator](https://enrich.chat/tools/email-permutator/) charts the study and lists every pattern to try.

## How does an email format finder work out the format?

An email format finder takes the addresses known to belong to people at a domain, matches each one to the person's name, and counts the patterns. The top pattern is the format. The rest are other formats seen.

1. **Collect known addresses.** One address is a clue. Several make a pattern. [Hunter's help center](https://help.hunter.io/en/articles/15921145-faqs-about-finding-emails-in-hunter), for example, says a domain's pattern appears only once "at least a few personal emails" have been found.
2. **Drop role inboxes.** Addresses like press@ and sales@ belong to a team, so they say nothing about how names are built.
3. **Match each address to a name.** sam.lee@ for Sam Lee is {first}.{last}. jdoe@ for Jane Doe is {f}{last}.
4. **Count and rank.** The most common pattern wins. A minority pattern usually points to an exception, such as an older rule or a shared name.

**Figure 1: From known addresses to a company email format.** Six example addresses at acme.com are each matched to a pattern. Four follow first.last, one follows first initial plus last name, and one is a press@ role inbox that is not counted. The most common pattern, first.last, used by 4 of 5 people, is reported as the format, with first initial plus last name listed as also seen.

*Match each personal address to a name, skip role inboxes, and count. The top pattern is the format. The addresses are illustrative.*

Enrich.chat's finder returns the most common format, an example address, the other formats seen at the domain, and a catch-all flag. The flag matters. A catch-all domain accepts mail for every address, including ones that do not exist, and [Google Workspace](https://knowledge.workspace.google.com/admin/gmail/advanced/get-misaddressed-email-in-a-catch-all-mailbox?hl=en) documents how admins send that mail to one shared mailbox. On such a domain, a mailbox check says yes to every guess, so the format is the best evidence you have.

## Why do some employees not match the company format?

A format is a default, and admins can override it. Exchange, for instance, lets admins apply a different template by company or department, according to [Microsoft's documentation](https://learn.microsoft.com/en-us/exchange/email-addresses-and-address-books/email-address-policies/email-address-policies). Four exceptions come up again and again.

### Duplicate names

When two people share a name, one of them gets a number or extra letters. The [University of Wisconsin-Stevens Point](https://help.uwsp.edu/TDClient/66/Portal/KB/Article/1679/Faculty-Staff-Email-Address-Information) gives staff two addresses: a username address made of the first initial and up to seven letters of the last name, and a First.Last address. A second hire with the same name gets a 2 on the full-name address and two letters of the first name in the username. When Army email at Fort Eustis moved to a Defense Department service in 2011, the sample address in the [base's announcement](https://www.jble.af.mil/News/Article-Display/Article/258530/eustis-e-mail-users-will-be-transitioning-to-army-enterprise-email-service/) also had a 2 after the surname.

### Subsidiaries and acquired brands

A company you buy often keeps its own domain. When Microsoft agreed to buy GitHub in 2018, it said GitHub would ["operate independently"](https://news.microsoft.com/source/2018/06/04/microsoft-to-acquire-github-for-7-5-billion/), and [GitHub's press page](https://github.com/about/press) still lists a github.com address. Google Workspace supports this setup with a [secondary domain](https://knowledge.workspace.google.com/admin/domains/add-a-user-alias-domain-or-secondary-domain), which gives a separate team its own domain, users and mailboxes. Run each domain through the finder on its own.

Domains also change. In 2010, Mark Zuckerberg said fb.com was [Facebook's new corporate email domain](https://venturebeat.com/business/facebook-fb-com), and staff had to move their work email off facebook.com.

### Contractors

Contractors may get a tagged address, or no address at the company at all. The Defense Department scheme in the [same announcement](https://www.jble.af.mil/News/Article-Display/Article/258530/eustis-e-mail-users-will-be-transitioning-to-army-enterprise-email-service/) added a status tag: .mil for service members, .civ for civilians, .ctr for contractors and .naf for staff paid from nonappropriated funds. Staff placed by an agency may write from the agency's own domain.

### Older addresses

When a company changes its rule, Exchange lets an admin turn off policy updates for any single person. Early hires and executives can keep an older format.

**Figure 2: Four reasons an address breaks the company format.** A company rule of first.last at acme.com covers most staff. Four exceptions branch off it: a second Jane Doe gets a number, as in jane.doe2; an acquired company keeps its own domain, as in jane.doe at oldco.com; a contractor gets a status tag such as .ctr; and an early hire keeps an older format such as jdoe.

*Four common reasons an address breaks the company rule. The addresses are illustrative. Sources: duplicate names from [UW-Stevens Point](https://help.uwsp.edu/TDClient/66/Portal/KB/Article/1679/Faculty-Staff-Email-Address-Information), the .ctr tag from [Joint Base Langley-Eustis](https://www.jble.af.mil/News/Article-Display/Article/258530/eustis-e-mail-users-will-be-transitioning-to-army-enterprise-email-service/), policy exemptions from [Microsoft Learn](https://learn.microsoft.com/en-us/exchange/email-addresses-and-address-books/email-address-policies/email-address-policies).*

## How do you find a company's email format by hand?

Find one personal address at the domain, then match it to the person's name. These five public places often have one.

1. **Press pages and releases.** Newsrooms and the media contact block at the end of a press release often show an address. Many are role inboxes. [GitHub's press page](https://github.com/about/press) lists press@github.com, which confirms the domain but not the pattern, so look for a named contact.
2. **Bylines and papers.** Company blogs, white papers and research papers often print the author's email. The [ICMJE recommendations](https://www.icmje.org/recommendations/browse/manuscript-preparation/preparing-for-submission.html) used by medical journals ask for the corresponding author's email on the title page.
3. **SEC filings.** For US public companies, [EDGAR full-text search](https://www.sec.gov/edgar/search/efts-faq.html) covers every electronic filing since 2001, exhibits included. Put the domain in quotes, such as "acme.com", to find contacts named in filings and attached press releases.
4. **Git commits.** Every Git commit records an author email, which the [Pro Git book](https://git-scm.com/book/en/v2/Getting-Started-First-Time-Git-Setup) says is "immutably baked into" the commit. A company's public repositories can show staff addresses. Many developers use a GitHub noreply address instead, and [GitHub's docs](https://docs.github.com/en/account-and-profile/how-tos/email-preferences/setting-your-commit-email-address) note that older commits keep the old address.
5. **PGP keyservers.** [keys.openpgp.org](https://keys.openpgp.org/about/faq/) returns a key only for an exact address, so it can test a guess but cannot list a domain. A key shows up in that search only after its [owner verifies](https://keys.openpgp.org/about/) the address.

Check your answer against a second person, since one address can be an exception. To skip the search, the [company email format directory](https://enrich.chat/email-format/) lists formats company by company, with pages such as the [Goldman Sachs email format](https://enrich.chat/email-format/goldman-sachs/). Our guides to [business email formats](https://enrich.chat/blog/email-address-formats/) and [finding anyone's work email](https://enrich.chat/blog/how-to-find-someones-email/) cover more methods.

## How do you turn a format into a verified email address?

Apply the format to your contact's name, then check the mailbox before you send. A format is a strong guess, and only a mailbox check or a reply confirms it.

1. **Apply the format.** With {first}.{last} at acme.com, Jane Doe becomes jane.doe@acme.com. Try the full first name too, such as robert as well as bob.
2. **List the options if the format is unclear.** If the finder shows two formats, or none, the [email permutator](https://enrich.chat/tools/email-permutator/) lists every likely address in your browser.
3. **Verify one address.** The [email finder](https://enrich.chat/tools/email-finder/) takes the name and domain, and labels the result verified, catch-all or unknown.
4. **Take care with catch-all domains.** If the domain is flagged, no check can confirm the person. Confirm the flag with the [catch-all checker](https://enrich.chat/tools/catch-all-checker/), send to the format you trust most, and watch for bounces.

If you start from a LinkedIn profile, the [LinkedIn email finder](https://enrich.chat/tools/linkedin-email-finder/) skips the format step. For a list of names, your AI agent can run the same checks through the [Enrich.chat API for agents](https://enrich.chat/agents/). It gets 10 free lookups a day. After that, monthly plans start at $29 for 100,000 credits, a work email found uses 10 credits, and a lookup that finds nothing uses 0. See [pricing](https://enrich.chat/pricing/) for every plan.

```text
Use www.enrich.chat to find the head of sales at acme.com, get their verified work email, and tell me if the domain is catch-all
```

## Can you find all email addresses on a domain?

Not with this tool, and no honest method gives you a complete list. A format finder tells you how addresses are built. It does not list the people behind them, for technical and privacy reasons.

- **Mail servers do not publish their mailboxes.** SMTP's EXPN command expands a mailing list, and VRFY checks one name. [RFC 5321](https://www.rfc-editor.org/rfc/rfc5321.html#section-7.3) lets sites turn both off, and notes that EXPN was used to "harvest" addresses for spammers.
- **Keyservers block it.** keys.openpgp.org allows exact matches only, which its [FAQ](https://keys.openpgp.org/about/faq/) says stops a spammer from getting a list of every address on the server.
- **US law punishes harvesting.** Under the CAN-SPAM Act, illegal commercial email becomes an [aggravated violation](https://www.law.cornell.edu/uscode/text/15/7704) if the sender knew the addresses were collected by automated means from a website that promised not to share them.
- **Privacy law adds duties.** The UK regulator says that if you get personal data from other sources, you must give people [privacy information](https://ico.org.uk/for-organisations/uk-gdpr-guidance-and-resources/individual-rights/the-right-to-be-informed/) within a reasonable period and no later than one month. Collecting a whole domain would create that duty for every person on it.

Domain search tools that do list addresses build them from published pages. [Hunter](https://help.hunter.io/en/articles/15921145-faqs-about-finding-emails-in-hunter) says it crawls public web pages and shows where it found each address.

A better approach starts from who you need. Describe the role in the [AI lead list builder](https://enrich.chat/tools/lead-list-builder/), or have your agent call `/v1/company/people` with the domain and a job title. Then get a verified email only for the people you will contact. Anyone can remove their data at [enrich.chat/opt-out/](https://enrich.chat/opt-out/).

## Frequently asked questions

### What is the email format for a company?

A company's email format is the pattern it uses to build work addresses, such as {first}.{last}@ or {f}{last}@. To find it, enter the company's domain in the email format finder on this page, or browse the [company email format directory](https://enrich.chat/email-format/). To work it out yourself, find one personal address at the domain in a press release, research paper, SEC filing or Git commit, and match it to the person's name. Check a second address, because exceptions exist.

### How accurate is an email format finder?

An email format finder tells you the rule most staff follow, not any one person's address. The format can be wrong for people with duplicate names, staff at acquired brands with their own domain, contractors, and early hires who kept an older address. Treat the format as your best first guess. Then confirm the address with the [email finder](https://enrich.chat/tools/email-finder/), which returns the work email on file with a status: verified, catch-all or unknown.

### Is this email format finder free?

Yes. Each visitor gets 10 free lookups, shared across Enrich.chat's free tools, with no signup. A domain with no match does not use one. For more volume, your AI agent can call the same API after reading one prompt, with 10 free lookups a day. After that, monthly plans start at $29 for 100,000 credits, and a work email found uses 10 credits. See [pricing](https://enrich.chat/pricing/) for every plan.

### What is the most common company email format?

It depends on company size. [Interseller's 2019 study](https://www.interseller.io/blog/2019/02/04/top-email-address-patterns-by-company-size/) of over 5 million companies found that first name only (jane@) led at companies with up to 50 employees, first initial plus last name (jdoe@) led from 51 to 1,000, and first.last (jane.doe@) led above 1,000. The study comes from a sales software vendor and is several years old, so check the actual company before you rely on it.

### What does it mean if a domain is catch-all?

A catch-all domain accepts mail sent to any address, even one that does not exist. [Google Workspace](https://knowledge.workspace.google.com/admin/gmail/advanced/get-misaddressed-email-in-a-catch-all-mailbox?hl=en) lets admins route that mail into one mailbox. Because the server says yes to everything, no verifier can prove that jane.doe@ belongs to a real person. The format finder flags catch-all domains so you know the format is your main evidence. Test a domain any time with the [catch-all checker](https://enrich.chat/tools/catch-all-checker/).

### Can I get a list of all email addresses at a company?

Not from this tool, and be careful with tools that offer one. Mail servers do not publish their mailboxes, and [RFC 5321](https://www.rfc-editor.org/rfc/rfc5321.html#section-7.3) lets sites turn off the EXPN command, which spammers used to harvest addresses. Under UK GDPR, if you collect personal data from other sources, you must give each person [privacy information](https://ico.org.uk/for-organisations/uk-gdpr-guidance-and-resources/individual-rights/the-right-to-be-informed/) within one month. Find the people you need by role instead, then get one verified email for each.

## Sources

1. [Email address policies in Exchange Server](https://learn.microsoft.com/en-us/exchange/email-addresses-and-address-books/email-address-policies/email-address-policies)
2. [FAQs about finding emails in Hunter](https://help.hunter.io/en/articles/15921145-faqs-about-finding-emails-in-hunter)
3. [Faculty/Staff Email Address Information](https://help.uwsp.edu/TDClient/66/Portal/KB/Article/1679/Faculty-Staff-Email-Address-Information)
4. [Eustis e-mail users will be transitioning to Army Enterprise Email service](https://www.jble.af.mil/News/Article-Display/Article/258530/eustis-e-mail-users-will-be-transitioning-to-army-enterprise-email-service/)
5. [Microsoft to acquire GitHub for $7.5 billion](https://news.microsoft.com/source/2018/06/04/microsoft-to-acquire-github-for-7-5-billion/)
6. [Press](https://github.com/about/press)
7. [Add a user alias domain or secondary domain](https://knowledge.workspace.google.com/admin/domains/add-a-user-alias-domain-or-secondary-domain)
8. [Mystery solved: FB.com is Facebook's new corporate email address](https://venturebeat.com/business/facebook-fb-com)
9. [Get misaddressed email in a catch-all mailbox](https://knowledge.workspace.google.com/admin/gmail/advanced/get-misaddressed-email-in-a-catch-all-mailbox?hl=en)
10. [Full-Text Search Frequently Asked Questions](https://www.sec.gov/edgar/search/efts-faq.html)
11. [Getting Started: First-Time Git Setup](https://git-scm.com/book/en/v2/Getting-Started-First-Time-Git-Setup)
12. [Setting your commit email address](https://docs.github.com/en/account-and-profile/how-tos/email-preferences/setting-your-commit-email-address)
13. [Preparing a Manuscript for Submission to a Medical Journal](https://www.icmje.org/recommendations/browse/manuscript-preparation/preparing-for-submission.html)
14. [Frequently Asked Questions](https://keys.openpgp.org/about/faq/)
15. [About keys.openpgp.org](https://keys.openpgp.org/about/)
16. [RFC 5321: Simple Mail Transfer Protocol](https://www.rfc-editor.org/rfc/rfc5321.html)
17. [15 U.S. Code 7704: Other protections for users of commercial electronic mail](https://www.law.cornell.edu/uscode/text/15/7704)
18. [The right to be informed](https://ico.org.uk/for-organisations/uk-gdpr-guidance-and-resources/individual-rights/the-right-to-be-informed/)
19. [Top Email Address Patterns By Company Size](https://www.interseller.io/blog/2019/02/04/top-email-address-patterns-by-company-size/)

## Find the people, not every address

Your agent can list the people at a domain by job title, then get a verified email for each one it needs. It gets 10 free lookups a day, and a lookup that finds nothing uses 0 credits.

```bash
curl "https://enrich.chat/v1/company/people?domain=acme.com&title=head%20of%20sales&limit=10"
```

## Try this prompt

Find the right person, then the email

```text
Use www.enrich.chat to find the head of sales at [company domain], get their verified work email, and tell me if the domain is catch-all
```

## Related

- [Email permutator](https://enrich.chat/tools/email-permutator/)
- [Catch-all email checker](https://enrich.chat/tools/catch-all-checker/)
- [Company email formats, A to Z](https://enrich.chat/email-format/)