This method scans additional mail address files compatible with m_inmail

Add this like to your lbdb rc file:

  M_INMAIL_FILES="<list of file basenames in .lbdb>"

Address files are expected to be inside of $HOME/.lbdb and contain the suffix utf-8

Location of lbdb rc file:

  $sysconfdir/lbdb.rc
  $HOME/.lbdbrc
  $HOME/.lbdb/lbdbrc
  $HOME/.lbdb/rc
