Disposable email address (DEA) is a temporary, throw-away address that expires after a short period of time. DEA provider websites offer a service where users can generate a temporary email address (with about a 10 minute lifespan, for example). Some of the most common DEA providers are 10 Minute Mail, Temp-Mail, and Fake Inbox.
Email address can be still disposable or non-existant, that's why not only we do internal database check, but also additional validation against email address DNS records. We check if domain has valid MX records and if its connected to one of disposable email providers.
There are also cases where email address providers are legit and well known, but mailbox account itself could be non-existent. In this case we must do real SMTP request directly to email address and see if we get successful response. This feature is currently under development.
We have up-to-date database with more than 30,000+ disposable email addresses and providers.
If you believe some email address is disposable and we haven't detected it - feel free to submit it here