i am new CI error while inserting database

[eluser]Unknown[/eluser]
i am not getting insert into the database. the error is

A PHP Error was encountered
Severity: Warning
Message: mail() [function.mail]: Failed to connect to mailserver at "localhost" port 25, verify your "SMTP" and "smtp_port" setting in php.ini or use ini_set()
Filename: libraries/Email.php
Line Number: 1252

and

An Error Was Encountered
Unable to connect to your database server using the provided settings.