First of all, assuming it's theft, without any evidence, is kind of accusing your carrier of stealing. You do have the same carrier on the route most days, and the utility the other day.

The post office does care, that's why they have Postal Inspectors... File a complaint, don't just show it to someone.

Now about the possible reasons for the "slit" package.

People don't pack things worth a $#!+ sometimes.

The machines, will squeeze the strike (or a coin) out the end. It falls on the floor and no one knows what envelope it came from, so it goes in the lost items. The "slit" is caused by the object itself.

Second if someone is stealing your coin/token they often _slam_ the envelope which pops the coin/token out the end of the envelope. Reinforce the end.

Right to all who said, pack it between something, not just loose in the envelope.

There are more losses because of poor packing, in the mail and in UPS, than from theft.

If someone is stealing from you, keep a record of dates and times, and nail them. Mail is hardly handled by humans except going to the sort and when your carrier delivers it. If those people want to throw away a nice government job for a loose coin, they deserve what they get.

If the machines are doing it, start looking at the way the strike was packed, and stop blaming the pickup person and the delivery person, who may be the only two people who ever touch your package from box to box.

That's right, hardly a human ever touches your mail anymore on it's way from the drop box to the mail delivery box.