Disposable email checker
Enter a domain or an address. We match it against 134 bundled entries, including wildcard parents, and show you which entry matched.
Why a disposable address verifies as valid
This is the part that surprises people. The mailbox is real. The domain has working MX records, the server accepts the recipient during the SMTP conversation, and any verifier asking the protocol question gets a clean yes.
What the protocol cannot express is that the mailbox will be gone in an hour, that it is public, and that nobody intends to read it. Those are facts about intent, and SMTP has no field for intent.
So detection here is list-based, and being list-based makes it honest about its own shape. It is deterministic: the same domain gives the same answer every time, and the answer names the entry it matched. That is worth more than a probability dressed up as a score.
The practical use is at the point of signup rather than at the point of sending. Checking a throwaway domain before it enters your database keeps the list clean at the source, which is cheaper than finding it later among your role addresses and old imports.
| Address type | Verifies as | Worth mailing |
|---|---|---|
| Disposable mailbox | Valid, because the server accepts it | No. Gone within hours |
| Role address such as info@ | Valid | Sometimes. Read by several people or none |
| Fresh free mailbox made to claim a trial | Valid, and no list will flag it | Rarely |
| Abandoned but existing mailbox | Valid | No, and nothing can detect this |
Blocking at signup, without blocking your customers
Decide by what the form gives away. A trial with real infrastructure cost behind it justifies a block, because the abuse case is someone cycling accounts. A newsletter almost never does, since the only thing at stake is one subscriber you were not going to reach anyway.
When you do block, say why. A form that rejects an address with no explanation loses the person who simply used the wrong mailbox by habit. One line naming the reason recovers most of them.
And keep the check at the edge. Blocking at signup is one decision on one address. Filtering your whole database later means a second pass over everything you already paid to collect.
Questions people ask
How many disposable domains exist?
Nobody knows, and the number changes daily. Public lists run from a few thousand to well over a hundred thousand entries, and the large ones include long-dead domains that pad the count without adding coverage.
Is a plus-address like name+shop@gmail.com disposable?
No. It delivers to a permanent mailbox the person reads, and they use it to see who sold their address on. Treat it as a real address, because it is one.
Why does your list look shorter than the ones vendors advertise?
Because it carries the providers people actually use plus wildcard parents that cover their subdomains, rather than every domain ever observed. Length is easy to advertise and does not improve the answer.
Do disposable addresses hurt sender reputation?
Indirectly. They inflate your list with mailboxes that never engage and often stop accepting mail later, which turns into bounces and poor engagement signals a few months down the line.
A list tells you about domains, not mailboxes
Verification asks the receiving server about the specific address, and reports the ones it could not settle rather than guessing at them.