Send emails using SMTP Yii 2.0

In your controller
Yii::$app->mail->compose()->setFrom('yyy@gmail.com')->setTo('sss@gmail.com')->setSubject('Email sent from Yii2-Swiftmailer')->send();

In common/config/main-local.php
 In components array
 'mail' => [
        'class' => 'yii\swiftmailer\Mailer',
        'transport' => [
        'class' => 'Swift_SmtpTransport',
        'host' => 'smtp.gmail.com',  // e.g. smtp.mandrillapp.com or smtp.gmail.com
        'username' => 'ttt@gmail.com',
        'password' => 'ggg',
        'port' => '587', // Port 25 is a very common port too
        'encryption' => 'tls', // It is often used, check your provider or mail server specs
        ],
        ],