CC, as I noted in the article, despite the relatively high prevalence of people with mental illness among Postal Service employees, the people who work there have a LOWER chance of being murdered on the job than the average U.S. worker (at all employers).

And given the overall high prevalence of mental illness among the U.S. (and world) population, "weeding out" people with mental illness histories from employment would reduce by millions the productive, tax paying work force, while increasing the dependent population.