subcommand for displaying support crypt algorithms.


- Aliases
    - avoid looping aliases

- Domain
    - optional limits for number of:
        + accounts
        + aliases
        + destinations/alias
        + alias domains

Database:
   public.users.digestmd5: add "character varying(48)"
	Outlook will love it. (`doveadm pw -s DIGEST-MD5.hex -p 1 -u 0`)

- Non-root usage [madduck@madduck.net]:
    - Provide /usr/share/vmm/vmm-{mkdirs,rmdirs,du} setuid wrappers that do
      precisely what they have to and no more. The should probably even call
      /usr/share/vmm/vmm-wrapper-helper as unprivileged user to parse the
      arguments, match them with the database and obtain the actual data to
      process, e.g. email@add.ress → home directory mapping from the DB, or
      obtaining the set of precreatable maildirs from the config.

    - configset and configure need root, it is questionable whether these
      can/should be wrapped, as they will be disabled anyway for Debian, and
      they are root-like activities (unlike day-to-day postmaster work).

    - Pascal suggested to use hooks:
      07 23:36 <Faxe> zwei config settings handle_dir in domain und account
      07 23:37 <Faxe> und dann post-{domain,user}add scripte, die den wrapper aufrufen