Disposable email checker: test one address or a whole list

By Ryan Doyle, co-founder of Sales.co. Published November 5, 2026.

A disposable email checker tells you whether an address sits on a throwaway domain such as Mailinator or YOPmail. Paste one address or a whole list below: each one is checked against 10,143 known disposable domains in your browser, with no signup. In a sample of 159,576 addresses from our own B2B contacts, none was disposable.

Data: 10,143 disposable domains, public-domain blocklist copied November 5, 2026. Rate in Sales.co's B2B contacts counted November 5, 2026.

How to read the result

• Disposable means the domain, or a domain it sits under, is on the list. Take it out of a campaign: these inboxes are temporary, so a send can bounce or go unread.
• Free mail means one of the 38 consumer domains our list counts use, such as gmail.com or yahoo.com. A real person may own it, and many small businesses use one.
• Business or other means the domain is on neither list. This says nothing about whether the mailbox exists, and a new throwaway domain lands here until the list catches it.
• Invalid means the address isn't shaped like an email, for example it has no top-level domain. Domains written with non-ASCII letters count as invalid; use their xn-- form.

How often this shows up in B2B contacts

We ran the same list against a random sample of 200,000 of its 4,000,550 contact records. Of 159,576 unique addresses on 119,068 domains, none was on a listed domain. With none found in that many addresses, the 95% upper bound on the rate is about 2 in every 100,000. Our contacts are prospecting data rather than signup forms, where people type a throwaway address on purpose. Even Gmail and Yahoo addresses are rare in them (11 in a 20,000-record check), so a rate of none describes mostly company-domain data. A list from a lead magnet or a free trial can look very different, so check it before you send.

Worked example

The ten example addresses above give 4 disposable, 2 free mail, 3 business or other and 1 invalid. tom@ridgelinehvac fails because it has no top-level domain. The clean CSV keeps the 5 addresses that are neither disposable nor invalid.

FAQ

What is a disposable email address?

A disposable email address is a temporary inbox from a service such as Mailinator, YOPmail or 10 Minute Mail. People use one to get past a signup form without giving a real address, so a message you send later is unlikely to reach the person who signed up.

How do I check if an email is disposable?

Compare its domain, the part after the @, with a list of known throwaway domains. Paste the address into the checker above and it does that against 10,143 domains, including subdomains of a listed domain. An address on a domain the list doesn't know yet comes back as business or other.

Can I check a whole list at once?

Yes. Paste up to 50,000 addresses, one per line or separated by commas, or copy a column from a spreadsheet. The checker removes exact duplicates, marks each address and gives you a CSV with the disposable and invalid ones taken out.

Is my list uploaded anywhere?

No. The domain list is downloaded to your browser and the matching runs there. The addresses you paste are not sent to Sales.co or anyone else.

Does this tell me whether a mailbox exists?

No. It checks the domain only and never contacts a mail server, so a real-looking address on a normal domain can still bounce. To test a mailbox you need an email verifier that talks to the mail server. Our free email list cleaner catches duplicates, typos and role inboxes.

How common are disposable addresses in B2B lists?

In a random sample of 200,000 of Sales.co's 4,000,550 contact records, none of the 159,576 unique addresses was on a listed domain, read November 5, 2026. Disposable addresses come from people filling in forms, so a list built from form fills is the one to check first.

Where the numbers come from

• Domain list: disposable-email-domains on GitHub, a community blocklist released under CC0, copied November 5, 2026 at commit a72c0cecfc. 10,143 domains. The checker also matches subdomains of a listed domain.
• B2B rate: Sales.co's B2B contact database (the contacts we gather for client campaigns), a random sample of 200,000 of its 4,000,550 contact records, read November 5, 2026. To confirm the count can find matches, we repeated it on a 20,000-record sample with gmail.com and yahoo.com added to the list, and that matched 11 addresses. Only domain counts leave the database, and no address is stored on this page.
• Free mail: these 38 domains. Our email list counts use the same list: gmail.com, yahoo.com, hotmail.com, aol.com, outlook.com, icloud.com, msn.com, live.com, me.com, mac.com, comcast.net, sbcglobal.net, att.net, verizon.net, bellsouth.net, cox.net, charter.net, earthlink.net, roadrunner.com, windstream.net, frontier.com, juno.com, mail.com, ymail.com, protonmail.com, proton.me, gmx.com, yandex.com, zoho.com, aim.com, netzero.net, optonline.net, embarqmail.com, centurylink.net, rocketmail.com, outlook.co, hotmail.co.uk, yahoo.co.uk.
• Price: $295 per list on sales.co/email-lists, read November 5, 2026.

If you'd rather start from a list built for one industry, Sales.co sells one-time business email lists at $295, and runs done-for-you cold email from $2,000 a month for up to 10,000 emails. See pricing.

Where to go next

all free Sales.co tools · free email list cleaner · email format finder · email spam checker · email lists