An email permutator takes a person's name and their company's domain and lists every common work email format they could have, such as first.last@, flast@ and first@. Type a name and a domain below to get the full list. If you know one colleague's address, add it, and the tool works out the company's format and puts the most likely address first.
Email permutator
Results update as you type. Example values are filled in.
Nothing you type is stored or sent anywhere. The tool runs in your browser.
How to use the email permutator
- Enter the person's first and last name as they write it, accents and all. Add a middle name or nickname if you know one.
- Paste the company domain. A full web address or someone's email works too; the tool keeps only the domain.
- If you know one colleague's email at the same company, add their name and address. This is the most useful step, because most companies use one format for everyone.
- Copy the list or download it as a CSV, then verify the addresses before you send anything. Never email every guess.
How it works: the patterns and cleaning rules
The tool first cleans each name so it can be used in an email address, then fills a fixed list of patterns. You can check any result by hand with these rules.
Cleaning. Letters are made lower case. Accents are removed (Zoë becomes zoe, José becomes jose). A few letters are spelled out: ß becomes ss, æ becomes ae, ø becomes o, œ becomes oe, ł becomes l. Apostrophes and dots are dropped, so O'Brien becomes obrien. Two-part first names are joined (Mary Ann becomes maryann). Characters outside a to z and 0 to 9 are dropped. Personal email domains such as gmail.com are refused, because guessing personal accounts mostly reaches strangers.
Patterns. With f for first name, l for last name and a single letter for an initial, the tool builds these, in this order:
| Pattern | Example for Jane Doe |
|---|---|
| first.last | jane.doe@ |
| flast | jdoe@ |
| first | jane@ |
| firstlast | janedoe@ |
| f.last | j.doe@ |
| firstl | janed@ |
| first_last, first-last | jane_doe@, jane-doe@ |
| last.first, lastfirst, last | doe.jane@, doejane@, doe@ |
| lastf, last.f | doej@, doe.j@ |
| fl, first.l | jd@, jane.d@ |
| last_first, f_last, f-last | doe_jane@, j_doe@, j-doe@ |
That is 18 addresses for a plain two-part name. A middle name adds five more (such as jane.m.doe@), a nickname adds four, and a double-barrelled last name adds five, using each half on its own and the hyphenated form. The order is a rough guide based on the formats we see most in B2B contact lists. It is not a measured statistic, which is why the colleague check matters more than the order.
Colleague check. The tool builds the same list for your colleague and looks for the pattern that produces their exact address. If dpark@ matches flast for Daniel Park, the flast address for your person goes to the top. If nothing matches, the company probably adds numbers or uses a custom format, and the tool says so.
Valid characters. Every result uses only a to z, 0 to 9, dots, hyphens and underscores, never starts or ends with a symbol and never has two symbols in a row. That keeps each guess inside the common subset of what the email format standard, RFC 5322, allows. Results are in lower case: RFC 5321 says relying on upper and lower case in the part before the @ "impedes interoperability and is discouraged".
Worked example: one colleague saves 833 checks
Say you want to email 50 people at the same company and you will verify each guess with an email verification service before sending. The numbers below are an example to show the arithmetic.
| Approach | Checks needed |
|---|---|
| Verify all 18 patterns for every person | 50 × 18 = 900 |
| Find the format once (up to 18 checks for the first person), then check one address each for the other 49 | 18 + 49 = 67 |
| Checks saved | 900 − 67 = 833 (about 93%) |
If you already know one colleague's real address, you skip the 18 checks too and need only 50. That is why the colleague field exists. The same logic works for a name with special characters: for Zoë O'Brien-Hall, the tool cleans the name to zoe and obrienhall and, with Daniel Park's dpark@ as the clue, puts zobrienhall@ first.
What good looks like, and what to do next
A permutator gives you candidates, not a confirmed address. A good outcome is one verified address per person and a bounce rate close to zero. Three rules:
- Verify before you send. An email verifier checks if a mailbox exists without sending a message. Some company domains are "catch-all" and accept mail for any address, so a verifier cannot confirm which guess is real. Treat a catch-all result as unconfirmed.
- Never send to every permutation. Most guesses do not exist, so a blast bounces. Google's email sender guidelines tell senders to unsubscribe recipients who bounce repeatedly and to keep spam rates in Postmaster Tools below 0.3%. The FTC's CAN-SPAM guide also treats generating addresses by dictionary attack as an aggravated violation, so stick to one verified address for a person you have a real reason to contact.
- Follow the law for every email. The FTC says CAN-SPAM makes no exception for business-to-business email, so include your postal address and a clear way to opt out. This is a summary of the FTC guide, not legal advice.
If you have a whole list with gaps, our guide to finding missing emails in a contact list covers doing this at scale. If you are not sure who to email in the first place, start with how to find the decision maker at a company. Before you hit send, run your draft through our spam words checker and plan your cold email follow up.
Need the addresses checked for you? Our Find customers range gets the right people into a spreadsheet with a checked work email for each, and every option starts free so you see real rows first.
FAQ
What is an email permutator?
An email permutator is a tool that lists the likely work email addresses for one person from their name and company domain. It combines the first name, last name and initials in the formats companies commonly use, such as first.last or first initial plus last name. It does not check if any address exists, so you verify the results before you send.
What is the most common business email format?
In the B2B contact lists we work with, first.last and first initial plus last name come up most, followed by first name only. We have no official statistic to quote, and formats vary by company size and country. The quickest way to know a company's format is to find one real address from a colleague and match its pattern.
How do I find out which permutation is the real email?
Run the candidates through an email verification service, which checks if each mailbox exists without sending a message. Start with the address that matches a known colleague's format. If the company's domain is catch-all, the verifier cannot tell which guess is real, so look for the person's address on the company website or in public posts instead.
Is it legal to guess someone's work email?
Working out an address is not itself banned, but what you send is regulated. The FTC says CAN-SPAM covers business email, and it treats generating addresses by dictionary attack as an aggravated violation. Contact one verified address for a real business reason, include your postal address and an opt-out, and check local rules. This is not legal advice.
Are email addresses case sensitive?
In practice, almost never. The email standard RFC 5321 says the part before the @ must technically be treated as case sensitive, but it also says relying on that hurts compatibility and is discouraged. Mail providers treat Jane.Doe and jane.doe as the same mailbox, so this tool writes every address in lower case.
Why does the tool refuse Gmail and other personal domains?
Permutations only make sense when one company controls the domain and uses a consistent format for its staff. On gmail.com or outlook.com, millions of unrelated people own the addresses, so a guess such as jane.doe@gmail.com probably belongs to a stranger. Use the person's company domain, or ask them for their address.
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