What “safe” means here
This inbox is generated at random and is not tied to your name. There is no password. Anyone who knows the live address can read incoming mail until the 5-minute timer ends. After that the address and messages are deleted.
That is safer than handing a newsletter your real address. It is less safe than a locked Gmail account. Do not put banking, medical, or work mail here. Do not use it to harass anyone or to commit fraud.
Is using temp mail legal?
Using a disposable address to avoid spam on a form is generally allowed. Impersonating someone, breaking into accounts, or using the inbox for scams is not. Follow the site’s terms and the law where you live.
This service receives mail only. It does not send as another person and it does not create @gmail.com addresses.
Can websites detect temp mail?
Yes. Many sites block known disposable domains. If a signup fails, the other site is filtering temp addresses. That is their policy. A fresh inbox on the same domain will often fail the same way.
Sites that accept the address still might delay mail. If temp mail is not receiving emails: keep this tab open through the queue, paste the exact address, wait a few seconds, and check spam is not relevant here — there is no spam folder. When the timer hits zero, start over.