Sending SMTP Email with Codeigniter 3 over Office365

ci_smtp_office365.php

/*
Minimun test code for successful email sending over SMTP with Office 365
Things to double-check: 
- openssl php extension must be enabled in the server
- host set to smtp.office365.com, not the old aliases
- Port 587
- newline configuration: explicit to "\r\n"
*/

//In your Controller code:
$config = [        
    'protocol' => 'smtp',
    'smtp_host' => 'smtp.office365.com',
    'smtp_user' => 'YOUR_EMAIL',
    'smtp_pass' => 'YOUR_PASSWORD',
    'smtp_crypto' => 'tls',    
    'newline' => "\r\n", //REQUIRED! Notice the double quotes!
    'smtp_port' => 587,
    'mailtype' => 'html'    
];
$this->load->library('email', $config);        

$this->email->from('YOUR_FROM_EMAIL');        
$this->email->to('TEST_EMAIL');        
$this->email->subject('Test');
$this->email->message('SMTP sending test');

$sent = $this->email->send();


if ($sent) 
{
    echo 'OK';
    
} else {
    echo $this->email->print_debugger();
}