A dispatch boat was a small spacecraft used for interstellar communication purposes.
They typically massed around 40,000 tons and had a crew of about ten. In order to provide message security, most modern vessels were designed not only with software and hardware firewalls, but also used physical separation to prevent systems such as navigational computers, which could be slaved to traffic control stations such as Manticoran Astro Control, from being used to access a message bank.
Dispatch boats were typically capable of high rates of acceleration, sacrificing comfort for speed, allowing some to pull 800 gravities of acceleration. (SI1)