To send mail using October CMS, follow these steps:Open your project in your preferred code editor.In the root directory of your project, locate the config folder.Inside the config folder, open the mail.php file.Set the driver option to the desired mail driver. October CMS supports various drivers such as SMTP, Sendmail, PHP's mail() function, etc.Configure the mail driver by setting the relevant options like host, port, encryption, username, and password.