At present, the following limitations are known to exist with this package,
 - Redirected E-mails can loop: If you setup one [hashed] user, let's call
   that user "jack" to redirect to another [hashed] user, "jill", and you
   have inadvertently previously setup jill to redirect to jack, the mail
   will loop. This is not detected by qmail's normal mail-is-looping
   mechanism, since that has been bypassed by this code. I believe I
   have a fix for this, but haven't had time to investigate thoroughly.
   That means that at present, you need to be particularly careful if
   you setup any redirections. If it's just delivery to Maildirs you do
   with this code though, you should be fine.
 - Update on the previous point: My intended fix with preline doesn't
   work, I think I need to get a better grip on the qmail code. This
   makes the fix less trivial, probably involving altering qmail
   itself (qmail-local or qmail-getpw) to do the hashing. All the
   admin stuff should still be OK though. Also note that the above
   looping problem should also be apparent if you 'redirect' jack
   to jack....!
 - You should make sure you're aware of the security issues with this
   code. For that, see the SECURITY text file.
 - As it currently stands, this code does not handle synonym domains
   well - i.e. if bob@somedomain is always going to be the same
   user as bob@someotherdomain, with the current system, you'll need to
   setup individual aliases for each user in the domains. I plan to
   rework the hashing, such that it hashes on domain separately to
   username. This will enable whole domains as well as just userames
   to be aliased.
 - Update on the previous point on synonym domains: I think this is
   trivially fixed with virtualdomains. Not checked this out yet.
