How to send email in cakephp 3.6.7..?

I am using cakephp3.6.7 while configuring app.php it will show error

error:
Could not send email: mail(): Failed to connect to mailserver at "localhost" port 25, verify your "SMTP" and "smtp_port" setting in php.ini or use ini_set()

please help me,

Thanks & regards,
Darshan