Rank 1 = 1 hour cooldown on each.. don't have $ for further ranks at the moment.
also.. mail droid looks like a probe droid from empire with a spherical head..
and repair droid looks like the ship repair droid..
If you want screenies... /w raive'harbinger on PTS
Rank 3 of mail droid is 15 min CD (forgot to look when i picked up rank 2)