[OpenAFS] mail spool on AFS

[Craig_Everhart@transarc.com]

Excerpts from mail: 20-Nov-01 Re: [OpenAFS] mail spool on.. Patrick
LoPresti@cag.lcs (1724*)

> Too bad you did not take one more step; you could have invented
> maildirs and avoided the need for any locks at all.

> See http://cr.yp.to/proto/maildir.html, but my quick summary is as
> follows:

> A maildir is a directory hierarchy that looks like this:

>         maildir
>         maildir/tmp
>         maildir/new

> To deliver a message, the MTA writes it as a new file under tmp, syncs
> it, and renames it to put it under new.  Clients look for messages in
> new, not tmp, so they never see any message until it has been fully
> written.  This obviates the need for locks.

Not a bad idea.  But our solution, with locks, also prevents collisions
between multiple simultaneous mail deliveries, as well as the occasional
multiple simultaneous mail readers, not just single-threaded mail
delivery vs. single-threaded mail reading.

		Craig