How to check email for existence?

Question

Email

Friends, hello everyone!
Can you tell me a tool for checking the email database for existence? Are there any such tools?

Answer 1

The most reliable way is to send a letter with a confirmation code (link), which the recipient will have to activate manually.
Less reliable - check through the callout mechanism. However, some systems at the initial stage of the session can give OK for their domains, regardless of the fact that the mailbox exists.

Answer 2

No.
Or more precisely, a refusal is definitely a refusal, but receiving a letter does not mean at all that it has reached the addressee. In corporate networks, very often non-existent mailboxes (fired, etc) are sent to "traps" - no one reads letters that have fallen there.

Answer 3

Is an Internet service of this kind suitable?

Answer 4

mail7.net here is another online service

Answer 5

mailify.ru is still a service, you can check the list, there is an api.