On Thu, 15 Jul 1999, Rik Hemsley wrote:
[...]
> Here's a description of how to write to Maildir from man 5 maildir:
> 
>        The tmp directory is used to ensure reliable delivery,  as
>        discussed here.
>  
>        A program delivers a mail message in six steps.  First, it
>        chdir()s to the maildir directory.  Second, it stat()s the
>        name  tmp/time.pid.host,  where time is the number of sec-
>        onds since the beginning of 1970 GMT, pid is the program's
>        process  ID,  and host is the host name.  

I do not understand what this is for. 
Can you please enlighten me?

>Third, if stat()
>        returned anything other than ENOENT,  the  program  sleeps
>        for two seconds, updates time, and tries the stat() again,
>        a limited number of times.  Fourth,  the  program  creates
>        tmp/time.pid.host.  Fifth, the program NFS-writes the mes-
>        sage to the file.  Sixth, the program link()s the file  to
>        new/time.pid.host.   At  that instant the message has been
>        successfully delivered.

--Stefan