I had a look at this PHP SMTP Email Validation and found it pretty useful.
How would I be able to post results to a MySQL database,
the info posted to the screen wont help if you have 100's of thousands of email addresses to validate.
250 user.example.com Hello example.com(22.214.171.124)
MAIL FROM: <email@example.com>
250 sender ok <firstname.lastname@example.org>
RCPT TO: <user1@Nexample.com>
250 Recipient ok <email@example.com>
A basic MySQL db could be like this;
CREATE TABLE `tblemail` ( `id` INT(3) NULL AUTO_INCREMENT, `txtmail` VARCHAR(100) NULL, `response` VARCHAR(20) NULL, `valid` VARCHAR(1) NULL, PRIMARY KEY (`id`) ) COLLATE='latin1_swedish_ci' ENGINE=MyISAM ROW_FORMAT=DEFAULT