What is the smtp server Codeigniter uses?

I don't have a smtp server on my machine, but Codeigniter allows me to send emails, how is that possible? Does Codeigniter comes with an smtp server?

Without any config it will use PHP mail function, check out below link for some setup instructions.
https://www.codeigniter.com/user_guide/l...references

Without any config it will use PHP mail function, check out below link for some setup instructions.
https://www.codeigniter.com/user_guide/l...references

Ok thanks! One more question, when I use php's mail function it requires me a smtp server but how come Codeigniter's usage of php's mail function doesn't?

PHP's mail function doesn't require SMTP, I think you might have a misconfiguration happening.  If you're using CI's mail to try and use PHP's mail, make sure your config is set to use PHP's mail.  See the link @ragingTouch posted.

specifically: 

PHP Code:

$config['protocol'] = 'mail';  // not SMTP or Sendmail 


Here's PHP's doc on mail.
http://php.net/manual/en/function.mail.php