How can I log failed mails into database using swiftmailer - yii2

Question

How can I check failed mails. Swiftmailer is returning true even if i supply invalid email address. I need to log send and failed mails into database
$message = Yii::$app->mailer->compose();
$message->attach($protocal.$_SERVER['SERVER_NAME'].$payslip);
$message->setTo("tft#sjkdsjk.dfdh");
$message->setFrom("hr#gmail.com");
$message->setSubject($vStaffName." ".$vPeriodName. " Payslip");
$message->setTextBody("Find attached copy of your payslip. To open this document use your ID number as password");
$send = $message->send();
var_dump($send);die(); //returns true always
I would expect true or false

Answer 1

You should check with SMTP.
That means you have to connect to that email's SMTP server.
After connecting to the SMTP server you should send these commands:
HELO somehostname.com
MAIL FROM: <no-reply#gmail.com>
RCPT TO: <emailtovalidate#domain.com>
If you get " Relay access denied" that means this email is Invalid.
There is a simple PHP class. You can use it:
http://www.phpclasses.org/package/6650-PHP-Check-if-an-e-mail-is-valid-using-SMTP.html