Split the query.
List<Email__c> e=[SELECT id, email_body__c FROM Email__C where id='emailobjectid'];
for(email__c e1:e){
List<Attachments> attList = [SELECT Id,Name FROM Attachments where parentId=:e1.id];
for(Attachment att:attList)
System.debug(att.id+' '+att.name);
}