Adam Di Iorio hadn't even received his new key from Canada Post before his community mailbox was hit again Monday night.

The Mississauga small business owner's community mailbox has now been broken into twice within a week — and three times overall this year. After a break-in last week, Canada Post changed the locks on Friday. By Tuesday morning, a thief had gotten in again.

"What's the definition of insanity again?" said Di Iorio on Tuesday. "Isn't it doing the same thing over and over again and expecting a different outcome?"

Di Iorio reached out to CBC Toronto last week, desperate for Canada Post to adopt "a better way" to deliver his company's mail after the second break-in. It had first happened in January, when Di Iorio says he found snow in his box, instead of the tenders and cheques he had gone to pick up.

"The amount of hours that were required to chase down lost funds was incredible," said Di Iorio, whose business supplies and installs fences. "We just resolved that a few weeks ago and now it's happened again."

With the third break-in, which happened after he spoke with CBC Toronto, Di Iorio now has even more work to do.

Canada Post says it will replace mailbox

CBC Toronto reached out to Canada Post again after the third break-in.

In a statement, the Crown corporation apologized to its customers for the inconvenience and said, "unfortunately, it appears this box has been targeted."

Canada Post says the mailbox will be replaced with a unit "configured for the customers it serves" within a week.

For a company with less than a dozen employees, Di Iorio says the effect of the break-ins has been "crippling" and has left him chasing down cheques when he should be out on job sites.

And it seems he's not the only one dealing with stolen mail.

When Di Iorio reached out to Canada Post about the situation last week, he says the Crown corporation told him there has been a "rash" of break-ins in mailboxes and it's an "on-going problem."

Adam Di Iorio says Canada Post told him there has been a 'rash' of break-ins in mailboxes and it's an 'on-going problem.' (Nicole Brockbank/CBC )

Last week, CBC Toronto reached out to the national mail service for numbers on reported mailbox break-ins across the country.

In a statement, Canada Post said it doesn't "divulge specific security measures or broader information related to our equipment publicly as doing so would significantly hamper their effectiveness." But the Crown corporation's operations team in Toronto said it was not "aware of any significant issues related to our equipment at this time."

The best case scenario, Di Iorio says, would be door-to-door delivery for his business. Otherwise, he wants a community mailbox installed that can't be pried open with a flat-head screwdriver — like the one he found on the ground beside his box a week ago.

I hope to God in this day and age that something exists that's better than this. - Adam Di Iorio, small business owner

"[The thieves are] in the mailbox in under 10 seconds," said Di Iorio. "I hope to God in this day and age that something exists that's better than this."

So does his neighbouring business, the Marriott Hotel Courtyard, which also gets its mail from the same community mailbox.

"At this point I really don't know what's missing," said Pragna Mistry, the hotel's accounting manager. "What's really critical for us is our guests that stay [long-term] in the hotel have their mail delivered here."

The locks on the community mailbox, near Derry Road and Hurontario Street, were changed following the January break-in, and again on Friday before the third break-in Monday night. In general Canada Post said it stands behind its equipment.

Community mailboxes 'put through rigorous testing'

In a statement, the corporation said, "any equipment we put on the street, such as a community mailbox, is put through rigorous testing, contains a number of security features and is monitored and maintained on a regular basis."

The Crown corporation delivers to 16.4 million addresses across Canada, and the biggest chunk of those addresses, 33 per cent, now receive their mail and parcels in a community mailbox. Another 27 per cent of addresses receive their mail through a group mailbox that is privately owned, according to Canada Post.

Group mailboxes can be found in apartment and condo buildings — or in business parks like those Daniel Caravaggio's company owns in Etobicoke.

Last month the mailboxes for Caravaggio's tenant companies at two of his properties were broken into, and in both cases the thief was caught on camera.

Watch the two break-ins for yourself in the video below.

The group mailboxes for companies at two Etobicoke business parks were broken into in September and the thief was caught on camera. 0:33

"I think that it would be fairly easy to find him," said Caravaggio. "There's a pretty good shot of his license plate."

The property owner reported the incidents to police and Canada Post — and says the Crown corporation told him there were hundreds of customers without mail due to community mailbox break-ins.

Caravaggio told CBC Toronto he had to buy his properties' mailboxes off a list of Canada Post approved equipment.

"I wish we could have bought something stronger at the time," he said. "It would be nice if Canada Post could specify tougher and higher standards for these boxes going forward, because it is a problem."