
* make it possible to give a list of target addrss or domains that are
  accepted, anything else is unknown
* make it possible to set the colors of the graphs
* consider drawing an y-axis at the right side, too, or at least gridlines
* more tests
* graphs with angled text at the bottom (like 45° since the email addresses or
  filter rules are pretty long)
* read in plain text files, not using zcat (for windows) 
