note fokat This is not really the fault of <tt>sendmail</tt> in modern versions. <tt>sendmail</tt> has no knowledge about the user's mailbox. This is the task of <tt>mail.local</tt>, which is the one responsible of dealing with mailboxes.<P> <tt>mail.local</tt> does require some form of file locking to prevent races in multiple message delivery scenarios. It attempts to use a number of schemes (<tt>fcntl()</tt>, <tt>lockf</tt>, <tt>flock</tt>, no locks at all) depending on the particular OS in which it is being installed.<P> Unfortunetely, locking does <b>not</b> work reliably in all the scenarios on all the OSes, so multiple schemes must be relied on if attempting to be portable.<P> 7058 9248