In the Montreal, St. Laurent sorting depot there was a rash of suicides a few years ago. The workers there were under tremendous pressure to increase their output. It's not like the old days when a door-to-door delivery mailman could finish his route in 3 hrs. Some used to farm out the route to a buddy for $10/hr and work at a second job.
There is now a 2 tier system of pay: the older guys get the great pay and pension, the new hires are paid a lot less and have a defined contribution pension.
As for lost mail, there was a Quebec postal worker who had years' worth of mail (packages, envelopes..all unopened) stashed at his cottage in the Laurentians. He was either mentally ill or lazy, I forget which.