A little distracted in the beginning but I will get to mail
The origin of the US Judicial term "Circuit" as as it is seen in the 8th Circuit Court of Appeals is derived from a circuit path that a full Judicial court would travel when frontier towns were not large enough to support major judicial functions.
All the necessary courtroom personnel would travel as a group from county to county to provide judicial services. Judges, stenographers, bailiffs, prosecutors, defense attorneys and civil litigators stayed in the country seat for a couple weeks to resolve the cases that needed to go to court (as now most cases were settled out of court but with the lawyer's assistance).
I imagine that both governments (Milgov/Civgov) in an effort to establish normalcy within their controlled territories would establish secure paths and use them to do the following:
Send Mail (Weekly or Bi Weekly)
Send Basic Medical services (Monthly or Bi Monthly)
Send Advanced medical services (every 4 months)
Send Legal teams (every 6 months)
I originally came up with this plan for my Morrow Project Game, as I planned to actually have my project work (they wake up after 5 years with a functioning prime base) but I wanted something that would keep my teams moving.