"Whatever." That was the brusque email response from a college professor that went viral and got dozens of students sharing tales of their own gruff lecturers.

Kade Walker, a student at South Dakota State University, shared a screenshot on Twitter of a short and casual-seeming email from his political sciences professor Dave Wiltse.

Joking about the difference in expectations between high school and college, Walker wrote: "High school: College is no joke, your instructors are very serious and you have to always be proffesional [sp] and respectful. College:" He then posted a screenshot of the email, which asked: "Is it still okay for me to take my final tomorrow at 12?"

After Walker ended his email with "Let me know," Wiltse replied with a simple "whatever" – without a capital letter or full stop.

Once the tweet had gone viral, Wiltse retweeted it in the most college professor way possible. He said: "tfw [the feeling when] your words go viral, and your punk student doesn't cite his source." His own tweet was shared even more widely, with 115,000 retweets and 386,000 likes, than Walker's original post which has now been retweeted 50,000 times.

Reflecting on the virality of the tweet, Wiltse added: "It was just a casual exchange between a prof and a student who like to give each other shit. And it blew up far beyond our circle for reasons I'll never know." He also said that Walker was one of his favourite students.

Wiltse told Buzzfeed News: "I'd no idea he tweeted it, until it started trending.

"I'm pretty short and terse in the emails that I send, particularly to people that know me, like Kade does. And I tell students, you know, I'm getting fifty-hundred emails a day, so you're going to get pretty short replies, and that's just how it is."

The tweets prompted many other college students and even professors themselves to share their abrupt, casual or otherwise amusing emails.

One professor was off sick because he had been bitten by a spider: "Unfortunately I don't think I'm turning into Spider-Man," he lamented. Another did not want to mark exams because it was his birthday, while a third sent an email to more than 70 students asking for the Real Slim Shady. One professor, upon being told a student would not be in class due to food poisoning, replied simply with: "Gross."

See some of the professors' emails below: