From Vast Empire Wiki
Note: Text directly from the Wookieepedia.
Most beings in the galaxy were either one of the two sexes of male or female. Some species such as the Hutts, however, could be both, classified as hermaphrodites; yet others had more than two (the insectoid Xi'Dec had over 180 different sexes). Other variable species like the X'ting changed gender every couple of months or years.
Droids, especially those with complex personalities and those which worked in close partnerships with organic beings, such as protocol droids and astromech droids, were often programmed as having either masculine or feminine character.