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

- relay_domains management [madduck@madduck.net]:

    - should be in a separate table

- default aliases [madduck@madduck.net]

    - it should be possible to define a set of default aliases and their

      destinations for a domain, e.g. postmaster@ and abuse@. For most

      flexibility, there ought to be a m:n table connecting domains to sets of

      default aliases. These aliases then get treated like normal aliases

      unless they are overridden by a real alias.