Some 40 years since the first electronic mail message was sent, users are still grappling with how to use the service properly and keep from making sloppy mistakes.
"We're still figuring out what are the social norms, what's acceptable, what's the right way to use it, what's not the right way to use it," said Levine, who authored the first "Internet for Dummies" manual in 1993 and "Email for Dummies" in 1997, and has worked with Industry Canada as a consultant.
"My most relevant message is: I have never regretted not sending a rude, snarky email. Somehow, no matter how careful you are, even if you're sending something to exactly the right person, the malicious-email fairy will wave her wand in front of your eyes for just enough seconds for you to push the wrong button and off it goes.
"We've all done this."
For his part, Kenney reportedly replied to an email about a possible meeting with Alberta's deputy premier, Thomas Lukaszuk, by calling him "a complete and utter a--hole." But instead of sending it to just one person, the email seems to inadvertently have gone out to a large circle of users and was passed around enough that it eventually became public.
For many, a reply-all mishap can be a valuable lesson about the perils of writing something you can't take back.
"Frequently I'm writing a message and I realize I need to stop and think. If somebody doesn't have all the context in my head, what will they think this message means? And frequently it's not what I meant," Levine said.
But even those who have made the mistake before aren't completely out of the woods, he adds.
"Partly, it's an issue of lousy user interface in mail programs. And partly it's a basic problem that sometimes it makes sense to reply to the individual and sometimes it makes sense to reply to everybody," he said.
"It's basically the same issue as when you're whispering to somebody and you don't realize there's a microphone on, or that other people can hear you."
The reply-all button can also create other problems that apologies can't fix. In extreme cases, an out of control spree of reply-all banter can wreak havoc on IT infrastructure. There's even a name for the sudden outbreak of emails triggered by flagrant abuse of the reply-all function: an email storm.
In 1997, Microsoft struggled to fight a Category 5 email storm when an employee on a mailing list with about 13,000 recipients asked to be removed. Unfortunately, the employee used reply all, as did a number of others who got the message and decided that they too wanted off the list. Then came the snarky messages urging others not to use reply all — while using reply all themselves — and the jokesters who figured it was the perfect time to share their best one-liner with thousands of their co-workers. IT staff watched helplessly as emails ricocheted from computer to computer and overwhelmed servers. The final tally: 15.5 million emails sent in less than an hour, adding up to 195 gigabytes of data, and two days of work until IT order was restored.
In 2007, the U.S. Homeland Security Department faced a similar but mercifully less intense email storm when a user on its antiterrorism-news mailing list sent an unsubscribe request to about 7,500 others. According to a New York Times report, the reply-all button spawned some 2.2 million messages, including no shortage of quips.
"Since we are introducing ourselves, I'm Steve and I like long walks on the beach and a nice chardonnay with my roasted duck. LOL," wrote one self-styled comic.
"May the fleas of a thousand camels infest you (sic) armpits," read a message fired back — with reply all, of course — by a frustrated user.