How to choose a program to check email addresses?

Question

Email Marketing

Good afternoon,
I am looking for a program or server to evaluate the relevance of email addresses. The list of contacts is large, one by one each email cannot be checked. There are many different programs offered on the Internet. Do not tell me which of them are the most effective and reliable? In order not to steal the list of contacts, etc.
Thanks

Answer 1

There is no 100% way to check the validity of an e-mail address. You can read why on the internet.