SendEmail.php

<?php

public function sendEmailToMembers()
{
  
  $sendEmail = function($member){
    
    $email = Email::create();
    $email->setTo($member->Email);
    $email->setFrom('your-email@address.com');
    $email->setSubject('Your Subject');
    $email->setTemplate('YourCustomEmail')
    $email->populateTemplate(array(
      'YourTemplateVariable' => 'Your value',
      'Member' => $member
    ));
    $email->send();
    
  };
  
  Member::get()->each($sendEmail);
  
}