My email signature is 10 lines incl. the attached text file which contain my disclaimer. So I don't know why your restricted to only two lines. Perhaps this is something Maximizer introduced after v7.0 (my ver.). Maybe someone who used v7 email signature feature can confirm if this was changed in v8 or v9.
Alternatively, you could put your signature in a text file and use the attach text file feature???
Iris