The hashing programs offered here make a number of assumptions - it is
important to understand these.

- For E-mail delivery, the domain information is *not* stripped off.
  Therefore, a hashed directory must exist that matches usernames *with*
  their domains. This may conflict with your authentication procedure,
  which typically will not include domains. In this scenario, you would
  setup a user and alias - for example (see USAGE.ADMIN for more info),

     addhashuser    username
     addhashmaildir username
     addhashalias   username username@domain

- Usernames are restricted to the characters defined in hash_core.h. If
  you wish to have usernames with other characters, you'll need to edit
  hash_core.h accordingly.

- Catch-all domain addresses are also possible. Suppose an E-mail arrives
  for joe@somedomain.com. The [hashing version of] qmail-local program will
  first hash "joe@somedomain.com" to see if there is a corresponding hashed
  directory.  If it doesn't find one, it will then hash "@somedomain.com"
  and check for a corresponding hashed directory. If it can't find one
  there, a permanent error is returned, bouncing the message (but see
  USAGE.NOTES).

