phpMailer

function mailTo ( $emails, $subject, $message ) {

    $mail = new PHPMailer;
    $mail->isSMTP();
    $mail->isHTML(true);
    $mail->setFrom( SITE_EMAIL, SITE_NAME );
    $mail->Host = 'smtp.gmail.com';
    $mail->SMTPAuth = true;
    $mail->Username = SMTP_LOGIN;
    $mail->Password = SMTP_PASS;
    $mail->SMTPSecure = 'ssl';
    $mail->Port = 465;

    if ( !is_array($emails) ) $emails = [ $emails ];
    foreach ( $emails as $key ) $mail->addAddress( $key );
    
    $mail->Subject = $subject;
    $mail->Body    = $message;

    return ( $mail->send() ) ? true : false;

}