Woocommerce plugin to validate email addresses with SMTP, including blacklist and whitelist

Goal is, to validate the email address, if the address exists. We want to prevent fake orders or testing order of the competitors. Features: - before sending a order, the customer email has to be validated with SMTP - we only want to check, if the email address exists - other errors should be ignored - if the customer email does not exist: order cannot be sent + error message is displayed to the customer with error message from the SMTP server + error log file is written - if the email domain does not exist -> error and log file written - if the SMTP server says „user unknown“ or similar -> error and log file written - if the SMTP server says „mailbox full“ -> no error - if the SMTP server says „IP blocked“ or „blacklisted“ or similar -> no error and log file written and email to the ADMIN - check this plugin with GMX, Gmail, Yahoo, Hotmail, t-online, AOL etc - whitelist: possibility to enter email addresses (e.g. name @ [login to view URL]) or email domains (* @ [login to view URL]) into a whitelist. That should be possible in the Wordpress admin as texfile. - blacklist: possibility to enter email addresses (e.g. name @ [login to view URL]) or email domains (* @ [login to view URL]) into a blacklist. That should be possible in the Wordpress admin as textfile. Important: we had problems, that we had been blocked in spam house blacklist, because they where thinking, that our email validator is a spam bot, because it was not „clean“ written. You have to take care, that the plugin acts exactly like a SMTP server with all commands and rules (like „quit“ to end etc). The script "[login to view URL]" causes spam blacklist problems, so it may not be used.