Some P.E.I. residents woke up Tuesday morning to find their new community mailboxes frozen shut, because Canada Post wasn't able to weatherproof them all before temperatures plunged below zero.

"There's been a lot of people stopped," said Mary Sharkey, who tried twice — unsuccessfully — to retrieve her mail from a community mailbox on Valdane Avenue in Charlottetown.

'I knew there'd be a problem with these.' — Velma Borsos, Charlottetown resident

"They're taking their keys, and trying to put them in, and fidgeting, and wondering, what the heck is going on?"

Residents had been using the boxes for a month without issue — but Monday's wet conditions combined with frigid temperatures overnight left some customers frozen out.

"I knew there'd be a problem with these," said Velma Borsos, who also tried her keys at the post boxes on Valdane Avenue on Tuesday.

Canada Post is taking the blame, saying the new boxes have a different lock design that is more susceptible to freezing.

"The first thing we want to do is apologize to our customers," said spokeswoman Anick Losier. "I don't think there's a suitable excuse at this time."

Winter coating

Losier said staff have been scrambling to cover locks with a special protective coating meant to prevent freezing, but the process is behind schedule.

Mary Sharkey

Charlottetown resident Mary Sharkey tries to get into her frozen mailbox using a barbecue lighter. (CBC)

"It should be done and we're going to work on rectifying this right away," she said.

Canada Post is not sure how many mailboxes have been affected or how long will it take to cover all the locks with the protective coating.

Residents like Sharkey worry what this means for the coming winter months.

"We're going to have a lot more rain and cold weather throughout the winter. So what is going to happen to our mailboxes?" she said.

"Am I going to have to bring a lighter down every day to heat up my key to open my box?"

Residents who urgently need a piece of mail and can't access it are asked to contact Canada Post, and staff will try to find a solution.

With files from Steve Bruce