Free tool, 200,000+ domain blocklist
Disposable email checker
Type in an address and the check runs on its domain. It goes through our blocklist of known temporary providers, then through the live DNS records that show whether mail could be delivered there at all. The inbox itself is never contacted.
Signals
What a full check looks at
Four fast checks, none of which require sending anything to the address.
Disposable domain
Matched against a list of 200,000+ known temporary and throwaway providers, refreshed continuously.
Mail servers (MX)
Every domain gets a live DNS query. If no MX record comes back, there is nowhere for mail to land, however ordinary the address looks.
Mail provider
Identifies who actually runs the mailbox: Google Workspace, Microsoft 365, a free consumer inbox, or a self-hosted domain.
Role address
Flags shared inboxes such as info@ or support@, which reach a team rather than a person and draw more complaints.
Background
Why they get through your form
A temp-mail service exists to give someone an inbox they intend to abandon. They take one to claim a trial, unlock a download, or collect a discount code, read the single message they came for, and leave. Most of those inboxes stop accepting mail within the hour.
Your form has nothing to object to. The address parses, the domain resolves, the mail server answers, and the confirmation message lands. A regex can only judge shape, and the shape here is correct, so validation lets it in.
That leaves the domain. Throwaway providers hand out addresses on domains they own, and those domains are what a blocklist tracks. This checker looks yours up there, then asks DNS whether the domain has anywhere to put a message in the first place.
What it costs you
- Hard bounces
- The inbox expires within the hour. Every send after that bounces, and a rising bounce rate is what moves your domain towards the spam folder.
- Distorted metrics
- Addresses that will never open or reply drag your rates down and hide how the people who matter are actually responding.
- Wasted spend
- Most sending and enrichment tools bill per contact. A throwaway address is budget spent on an inbox that stopped existing.
- Trial farming
- The same trick powers bulk free-trial signups and bot registrations, which inflate your numbers and your infrastructure bill at once.
At scale
Running the check over a full list
Spot-checking one address is easy. The work that takes time is a list with thousands of rows in it. Drop in a CSV, or paste the column straight out of your spreadsheet, and the same blocklist runs against every row. Anything disposable comes back labelled, so you can pull those rows before the send.
The blocklist judges a domain. An SMTP check judges one mailbox, and that is the step paid verification adds on top of this free tool. It opens a conversation with the receiving server to establish that the specific address is there, sorts catch-all domains into a category of their own, and leaves unknowns off your bill when a server will not answer.
The API moves the same check onto your signup form. It answers in real time, so a throwaway domain is rejected at registration and no account gets created for it. Ask us about API access.
Questions
About disposable addresses
What is a disposable email address?
A temporary inbox created to receive one or two messages and then disappear. Someone uses it to claim a trial, grab a download, or dodge a newsletter, and within the hour it stops accepting mail. They are also called throwaway, burner, or temp-mail addresses.
Why do they get past normal form validation?
Because nothing about them is malformed. The syntax is valid, the domain resolves, the mail server answers, and a confirmation email arrives. A regex has no way to tell the difference. The only reliable signal is the domain itself being a known throwaway provider.
Can somebody get around a blocklist?
Throwaway providers spin up faster than any blocklist can absorb, so completeness is not on offer from anyone, and anyone claiming a perfect catch rate is overselling. We combine a large refreshed blocklist with live DNS checks and, on paid plans, full mailbox verification, which catches throwaway and dead addresses from several directions at once.
How do I clear them out of a whole list?
Create a free account and run the list in bulk. Disposable domains are flagged automatically, and full verification also strips out the mailboxes that no longer exist and separates the catch-all domains.
Get started
Clear the throwaway addresses out of your whole list
Bulk verification flags disposable domains, confirms the real mailboxes over SMTP, separates the catch-alls, and never charges for an unknown.
- Free credits
- 200
- Card required
- No
- Unknown results
- Never charged