Drive around Saint Denis, or Blackwater to different locations and deliver packages!
To begin the Post Worker job, head to either Saint Denis or Blackwater, and then enter the telegrams office. You will see a prompt [Space to start mission] You will deliver 5 packages to random businesses, and residences within the area. You are paid at the time of dropping off each package, not when you return to the office. This is not a timed job.