Disposable email checker
See whether an address uses a temporary, throwaway email service. Also catches typos, role accounts and domains that can’t receive mail.
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How the disposable email check works
The disposable email check tells you whether an address or domain belongs to a temporary, throwaway email service, and flags typos, role accounts and domains that can’t receive mail. It is for anyone who runs a sign-up form, cleans a mailing list or reviews new accounts and wants a quick signal before trusting an address.
How a domain is matched
The domain and each parent domain are checked, but never the top-level domain on its own, so inbox.tempmail.example also matches a listing for tempmail.example. The result then says which listed name it fell under. Hashes are compared on their first 24 hex characters (96 bits), so a false match with another listed domain is practically impossible.
How the list is kept current
The two source lists are downloaded and merged on the server once a day. If a download fails or takes longer than 25 seconds, or a list grows or shrinks by more than 20% since the last good copy, the previous list stays in use rather than one that may be broken; a new size that holds steady for 7 days is then accepted, so one real jump upstream can’t freeze the list. Entries for big mailbox providers are dropped while the list is built. Their regional domains are spelled out one by one, so look-alikes the lists flag, such as outlook.sbs, aren’t exempted. The result shows when the list last changed and when it was last refreshed, and says so when the daily refresh is overdue.
How the notes are worked out
- Typos. The domain is compared with a list of popular mailbox domains. One slip, with two swapped letters counted as one, is enough for names of six characters or more; two slips only count in longer names.
- Role accounts. The part before the @ is matched against common role names such as
info,supportandnoreply, ignoring dots, hyphens, underscores and anything after a+. - Mail servers. With no MX record but an address record, senders fall back to that address, which is shown as a warning. With neither, or with no such domain, mail can’t be delivered. A lookup that fails shows as couldn’t check, never as a problem with the domain.
- Address syntax. Display names such as
Jane <jane@example.com>andmailto:links are accepted. Internationalized domains are checked in their DNS form, and an address with an IP address instead of a domain can’t be checked.
Checking a list
In the list tab, a header row is skipped, files up to 5 MB can be opened, and mail servers are checked for the first 500 distinct domains. The table shows the first 1,000 rows and can be filtered to disposable addresses or to every row that needs attention; the CSV download has all of them. A cell that starts like a spreadsheet formula gets a leading apostrophe, so it can’t run as a formula when you open the file.
For an address you plan to email, the email address checker adds a live check with its mail server, and the blacklist check shows whether a domain is on DNS blocklists.
Updated · Maintained by Liviu Tanase
Questions
What counts as disposable here?
The domain, or a parent domain, is on one of two open-source lists of temporary email services: disposable/disposable-email-domains (MIT) and disposable-email-domains/disposable-email-domains (CC0). Both are merged and refreshed every day. The stricter variants that also include anonymous but legitimate providers are not used.
How does the list check work?
Your browser hashes the domain with SHA-256 and asks the server for the bucket of listed hashes that start with the same two hex characters, one of 256 buckets, and the match happens in your browser. The address you typed is kept in the page address so you can share the result, and page addresses pass through Cloudflare like any web address. The list requests carry only the hash prefix, never the page address.
A domain isn’t on the list. Is it legitimate?
Not necessarily. Not being listed means only that: new throwaway services appear every day. The MX, typo and role-account notes help, but no list can prove an address is real. Gmail, Outlook, Yahoo, iCloud, Proton, GMX, Yandex and other big mailbox providers are never flagged.
What do the notes on each address mean?
Syntax checks the address against the email standards. A role account such as info@ or noreply@ reaches a team or nobody, not a person. Free mail means a personal mailbox provider rather than a company domain. A typo note suggests a likely intended provider, for example gmial.com to gmail.com. The mail server check reads the domain’s MX records: a domain with no mail servers, or a null MX (RFC 7505), can’t receive email.
Who sees the domain when the mail servers are checked?
The MX lookup is a DNS query your browser sends straight to Cloudflare’s public resolver (or Google’s, if Cloudflare doesn’t answer). It never goes to zerobounce.ai. Turn the option off to skip it.
Can I check a whole list?
Yes. Paste up to 5,000 addresses or open a CSV file; it’s read in your browser, never uploaded. Every cell with an @ is checked. Download the results as CSV.
How often is the disposable domain list updated?
Every day at 04:23 UTC both lists are downloaded and merged on the server. If a download fails, or a list’s size changes by more than 20% from the last good copy, the previous merged list stays in use; a new size that holds steady for 7 days is then accepted. Each result shows when the list last changed and when it was last refreshed.
How is this different from the email address checker?
The email address checker uses the same merged lists and the same matching, so both give the same answer about a domain, and it adds a live check of the address with its mail server. The full report runs both, plus the domain’s mail and web checks.
A domain is listed by mistake. How do I fix it?
The lists are maintained on GitHub. Open an issue on the list that names it, linked from the result, so the fix reaches everyone who uses it.