I checked my list and sent emails to “Good” addresses, but I still received bounce messages with the delivery failure error. How can I have 100% accurate results?

Although the Advanced Email Verifier has a very good email validation success rate with most free email ISPs or ESP, it is simply not possible to guarantee a 100% accuracy level due to certain multiple factors beyond our control. The level of accuracy you can obtain depend on the inbound SMTP connection policy of the remote ISP or ESP, reputation of the incoming connecting IPs and many other factors.

Advanced Email Verifier connects to the email addresses mail server, as part of the validation process, and asks if the user exists but NEVER send an email to the recipient. If the recipient’s server gives the response that the user exists, the Advanced Email Verifier marks the email address as good. If the mail server says that there is no such user, AEV marks the email address as bad. This means that the Advanced Email Verifier classifies the email address depending on the response of the recipient’s mail server.

But some mail servers are configured so that they always give the response that the user exists. This means that you may get a number of false positive results and may receive bounced emails after you sent the message to the email addresses determined as good by the Advanced Email Verifier.

You can get the highest accuracy in list cleaning if you install the Advanced Email Verifier on a Windows VPS with a mail server, clean IP address, and FCrDNS and PTR records properly setup.

If you don’t have knowledge how to configure the VPS, you can consider using BPSocks email validation API. But this mode requires the purchase of API keys from the 3rd party company. Their prices starts from $50 for 50,000 email addresses.

Interested? Learn more about our Advanced Email Verifier software.