Restricting the user to create duplicate email(Contact) for a particular account

Apex class
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public class DuplicationOnContact {
    public static void doDuplicateCheck(List<Contact> conlist){
         Map<String,String> mapcon=new Map<String,String>();
        set<String> setacc=new set<String>();
        for(Contact con:conlist){
            if(con.AccountId!=null)
                setacc.add(con.AccountId);
                }
 
    for(Contact con:[select Id,Name,Email,AccountId from Contact where AccountId=:setacc]){
         mapcon.put(con.Email,con.AccountId);
    }
    for(Contact con:conlist){
        if(!mapcon.isEmpty() &&  mapcon.containskey(con.Email)){
            con.addError('Please enter unique Email');
        }
    }

    }
}

Trigger
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Trigger ContactTrigger on Contact(before insert,before update){
       DuplicationOnContact.doDuplicateCheck(Trigger.new);

   }

//It will be fired when the user creates a contact with email(which already present in the database) for a particular account