smtp.php

$mail->Host = "HOSTINGER_SMTP_HOST_HERE";
//Set the SMTP port number - likely to be 25, 465 or 587
$mail->Port = HOSTINGER_SMTP_PORT_HERE;
//Whether to use SMTP authentication
$mail->SMTPAuth = true;
//Username to use for SMTP authentication
$mail->Username = "YOUR_SMTP_USERNAME";
//Password to use for SMTP authentication
$mail->Password = "YOUR_SMTP_PASSWORD";
//Set who the message is to be sent from
$mail->setFrom('YOUR_SMTP_EMAIL', 'First Last');
//Set an alternative reply-to address
$mail->addReplyTo('replyto@example.com', 'First Last');
//Set who the message is to be sent to
$mail->addAddress('YOUR_EMAIL_ADRESS_WHERE_YOU_CAN_CHECK', 'John Doe');