Send an email when an exception is catched.

Exception_to_email

try{
  update account;
} 
catch (DMLException e){
  ApexPages.addMessages(e);
  
  Messaging.SingleEmailMessage mail=new Messaging.SingleEmailMessage();
  String[] toAddresses = new String[] {'developer@acme.com'};
  mail.setToAddresses(toAddresses);
  mail.setReplyTo('developer@acme.com');
  mail.setSenderDisplayName('Apex error message');
  mail.setSubject('Error from Org : ' + UserInfo.getOrganizationName());
  mail.setPlainTextBody(e.getMessage());
  Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
}