How to use mail() instead of smtp?

I use the last version of ojs 2.

In the config.ins.php file it is mentioned that
Use SMTP for sending mail instead of mail().

If want to use mail() instead of smtp what I should do?
As it has been mentioned in may places to use smtp with gmail one should use the following

; Use SMTP for sending mail instead of mail()
smtp = On

; SMTP server settings
smtp_server = “ssl://”
smtp_port = 465

; Enable SMTP authentication
smtp_auth = PLAIN
smtp_username = “
smtp_password = “password”

If I want use mail() what are the correct settings to use gmail?

Please comment lines with smtp in order to disable it.
OJS will use (mail) by default in that case.

I have done it but nothing happens. By the way, if I comment email credentials (including user, password etc) how mail() find out the correct credentials in order to send email?

You comment only things related to smtp. Php mail function will directly communicate with e-mail server. Is your e-mail server functional?