QLDAPPICTURE

 1. qmail-smtpd accepts connection

    Is relayclient set?
      Yes -> accept it anyway.
      No  -> check if recipient domain is listed in rcpthosts else
             deny

    Does sender's domain have a valid MX or A record?
      Yes -> accept for data
      No  -> deny

    Now the message gets queued.

 2. qmail-send takes a look at it

    Is the recipients domain in virtualhosts or locals (doesn't matter
    with qmail-ldap)?
      Yes -> feed it to qmail-lspawn for local delivery
      No  -> feed it to qmail-rspawn for remote delivery (relaying as
             usual)

 3. qmail-lspawn gets it for local delivery

    Is the recipients full email address found in the LDAP directory?
      Yes -> check if all needed attributes are present
               Yes -> deliver it to the maildir
               No  -> bounce
      No  -> try a standard qmail (UNIX user or ~users/assign) delivery