Directory management for mass virtual Maildir email

[Scott Edwards <supadupa@gmail.com>]

At the onset, I decided to just keep all email accounts (in Maildir
format) below /var/mail/user@host/.  This is working ok for now, but
I'm sure after I approach a few hundred accounts, it will become less
desirable.  The billing management system uses unique numerical id's i
can use.  The directory location for each account is stored in a
virtual email table in the database accessible by the smtp, pop3, imap
and webmail services. (postfix, courier, sqwebmail).  A few trivial
modifications to the provisioning script I have is all that should be
necessary to put something new in place. (optionally moving existing
accounts to their new home).  There are only a few accounts handled
via local mail, everything else is virtual mail.

Using numerical account id's (or any suggestion you can offer), what
are the most scalable options for this scenario?  There's only a few
hundred email accounts right now, but what options should i consider
to keep the directory sane when I approach hundreds of thousands of
accounts?  I am using ext3fs under a 2.6 Linux kernel, but may
consider some type of NFS further down the road.

I look forward to any worthwhile input you may provide.

Thanks,


Scott