During email verification, we create an SMTP connection with the recipient server. This is the same connection when sending an email. The only difference is that we abort the connection before sending an email.
We base our results on our response from the mail server we are connected to. Unfortunately, email sending is one of the most fragile communication methods. There are countless reasons why the delivery of an email may fail. We have built a solid email verifier software that can handle tens of millions of verifications daily with minimal downtime and rare errors.
We review our accuracy regularly and keep responding to any changes we experience. However, no matter how much effort we invest, email marketing, including email verification, never be 100% accurate.
We are proud to achieve 99% accuracy, thanks to our regular reviews. 99% accuracy also means that 1 % of the verifications may not be accurate. It is due to the instability of email marketing. For example, if a domain's DNS server is not available for any reason (e.g., the server is down for several minutes, or there is a network error), we are unable to retrieve their mail server information, and we can't verify the email at the time of the verification.
We are going to continue working on improving our accuracy. We investigate every feedback and complaint about our accuracy and make necessary changes to improve. Results may change from time to time. Emails that exist one day may not exist the next day or the other way around.
