обрабатывать сообщения (process messages)
Статус выхода (Exit)
When the -e option is specified, the following exit values are
returned:
0 Mail was found.
>0 Mail was not found or an error occurred.
Otherwise, the following exit values are returned:
0 Successful completion; note that this status implies that
all messages were sent, but it gives no assurances that any
of them were actually delivered.
>0 An error occurred.
