send_email.php

<?php
private function resendActivation($email) {
		$user = User::find()->where(['email' => $email])->one();
		$baseUrl = join('', [Yii::$app->params['absolute_url'], Yii::$app->urlManager->baseUrl]);
		$yiiTransport = Yii::$app->mailer->transport;
		$view = Yii::$app->mailer->render('user_activation', ['baseUrl' => $baseUrl, 'model' => $user,
			'userProfile' => $user->userProfile
		]);

		$transport = \Swift_SmtpTransport::newInstance($yiiTransport->getHost(), $yiiTransport->getPort())
			->setUsername($yiiTransport->getUsername())
			->setPassword($yiiTransport->getPassword())
			->setEncryption($yiiTransport->getEncryption());

		$mailer = \Swift_Mailer::newInstance($transport);
		$signupParam = Yii::$app->params['mail']['signup'];
		$message = \Swift_Message::newInstance($signupParam['subject'])
			->setFrom([$signupParam['from'] => $signupParam['fromName']])
			->setTo([$user->email => $user->userProfile->full_name])
			->setContentType('text/html')
			->setBody($view);
		$mailer->send($message);
	}