Getting Internal Server Error(500) while sending email using php(Codeigniter)

Hai there,

I'm getting internal server error while sending email using codeigniter. I used the following smtp cofiguration to send mail,

$email_config = Array( 'protocol' => 'smtp',
'smtp_host' => 'mail.domain.com',
'smtp_port' => 465,
'smtp_user' => 'no-replay@domain.com',
'smtp_pass' => '*****',
'mailtype' => 'html',
'charset' => 'iso-8859-1'
);