global class sendEmail implements Schedulable {
   global void execute(SchedulableContext SC) {
sendEmail();
   }

   
  global void sendEmail(){

        Messaging.reserveSingleEmailCapacity(2);
        

        Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
        
        // Strings to hold the email addresses to which you are sending the email.
        String[] toAddresses = new String[] {[Select EmailAddress__c From CS_EmailAddresses__c Limit 1].EmailAddress__c};
          
        // Assign the addresses for the To and CC lists to the mail object.
        mail.setToAddresses(toAddresses);
        
        // Specify the address used when the recipients reply to the email. 
        mail.setReplyTo('mycompany@mydomain.com');
        
        // Specify the name used as the display name.
        mail.setSenderDisplayName('Salesforce Email Reminder');
        
        // Specify the subject line for your email address.
        mail.setSubject('Yearly Email Reminder');
        
        // Set to True if you want to BCC yourself on the email.
        mail.setBccSender(false);
        
        // Optionally append the salesforce.com email signature to the email.
        // The email address of the user executing the Apex Code will be used.
        mail.setUseSignature(false);
        
        // Specify the text content of the email.
        //mail.setPlainTextBody('Please configure this');
        
        mail.setHtmlBody('Your Invitee batch job has been processed.<br/><br/>Best Regards);
        
        // Send the email you have created.
    Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
    }
}
   }

sendEmail sendEmailJob = new sendEmail();
        String sch = '-- CRON EXPRESSION';
        system.schedule('sendEmailJob', sch, sendEmailJob);