Email verifier module in ab bulk mailer allows removing incorrect mails from your maillist. Sending mails to non-existing email causes not only blocking of sending accounts, but can also defeat the purpose of sending email. It takes much time and affort to send marketing mails. So if your list is totally incorrect, the mails go spam or are never delivered.Marketing should be such that efforts spent on email marketing should be rewarded quickly.
If you click on email verifier button in ab bulk mailer you see something like below:-
It will show you some non-existent emails that system found invalid. By invalid it means that email address is incorrect and does not exist on the server. You can simply add these emails to black list or delete them here also by clicking delete button. Removing incorrect emails from your marketing list is a big challange for you and ab bulk mailer will help you in that. Most of the companies charge for email verification but ab bulk mailer gives this feature as free with ab bulk mailer purchase.
The intelligent option to verify only domain name can save a lot of time to remove 90% incorrect emails. And if you have time you can then click verify button to verify every mail one by one using multi-threading handshaking with email servers. AB Bulk mailer verifies 500+ emails at a time and is multi-threaded.
Rigid security option is an option for extra vigorous intelligence against weak smtp servers. Usually it should not be used every time.