With the Byteplant Email Validator plugin you can easily verify if an email address really exists and is valid (http://www.email-validator.net).
This plugin uses the Byteplant Email-Validator API (http://www.email-validator.net) to check if an email address really exists or not.
The plugin integrates with the is_email() function of WordPress. It works seamlessly with:
The plugin can also be integrated into 3rd party forms that do not use the is_email() function.
The Email-Validator API real-time validation process includes all of the following tests:
The plugin requires an API Key (free, no credit card required): http://www.email-validator.net/email-validation-online-api-get-free-trial.html
We do not send any email to the recipient address during the entire validation process. All processing is done on our servers, your IP addresses and domains are not affected in any way by the Email-Validator service - absolutely no blacklisting risk for your IPs and domains.