Hi,  
I have a small issue regarding emails.

I have Enterprise Edition with 447 user Licences and I have nearly 1,00,000 Accounts in my Account Object, I need to send an email to those Accounts at a time.
To send Email I scheduled a class a Batch Class , Here is the Batch Class .

global class SurveyBatchProcessForActiveAndInactive implements Database.Batchable<Opportunity>
{   
    //Query Opportunity fields with active,inactive stages and Department is Aus and also RecordType is AUS
    
    global Iterable<Opportunity> start(Database.BatchableContext BC)
    {
        Opportunity[] opp=[select id,Account.Person_Email__c,Account.Id from Opportunity where Account.Person_Email__c != Null];
        system.debug('Opportunity Size'+opp.size());   
        return opp;
    }
   
    //sent email to opportunity clients those are returned by start method
         
    global void execute(Database.BatchableContext BC, List<Opportunity> opprecords)
    {
        List<Messaging.SingleEmailMessage> mails  = new List<Messaging.SingleEmailMessage>();
           //To sent email to clients
           for(Opportunity opp:opprecords)
           {
            Messaging.SingleEmailMessage email = new Messaging.SingleEmailMessage(); 
            List<String> toAddresses = new List<String>(); 
            toAddresses.add(opp.Account.Person_Email__c);                                
            String htmlbodystring  = 'Some Text goes Here'+opp.id;   
               
                  email.setToAddresses(toAddresses);
                  email.setHTMLBody(htmlbodystring);
                  email.setSubject('Test');
                 
                  mails.add(email);    
         }         
         Messaging.sendEmail(mails);  
    }
   
   //Life Cycle method of Batch Class
    global void finish(Database.BatchableContext BC){
         
    }
}


While running this class, I got SINGLE_EMAIL_LIMIT_EXCEEDED error. How to Solve this issue please help me