I have created an email function with CodeIgniter and I used its email library with the smpt configuration and it's working on my local machine, and when I uploaded in my droplet the email function does not working now (it doesn't send email using CI Email lib). What could it be the possible cause that it's not working on my server? Using this configuration: $config['protocol'] = 'smtp'; $config['mailtype'] = 'html'; $config['smtp_host'] = 'ssl://smtp.gmail.com'; //'ssl://smtp.googlemail.com'; $config['smtp_user'] = 'email_address'; $config['smtp_pass'] = 'password'; $config['smtp_port'] = '465'; $config['charset'] = 'utf-8'; $config['crlf'] = "\r\n"; $config['newline'] = "\r\n"; Here is the link to the function and it shows the error with the smtp validation/authentication: http://postfor.us/construction/test_mail Please have a look, and if you have a solution for this issue. Please let me know.