eMail Verifier verifies every e-mail address from a given mailing list, allowing you to determine up to 80% of "dead" mail addresses. For some addresses, such as AOL, Yahoo, and other non-SMTP mail, you can't verify whether the address is good or not. You won't know definitively until some bounce. The mail server won't cooperate.
In fact, a few ISP's mail servers are configured in a way they prevent anybody to find out if an e-mail address is good or not sometimes to protect their customer e-mail addresses from harvester tools.
Consider eMail Verifier as a tool for tracking bad e-mail addresses instead of validating good ones.
