This 18-year-old college student accidentally emailed thousands of classmates—it turned his pet-sitting business into a valuable side hustle

Hector Gutierrez became an overnight campus celebrity at the University of Alabama earlier this year after an embarrassing email faux pas put him in the spotlight.

While applying for the school’s honor society, he mistakenly sent his business school professor’s recommendation letter to a college listserv with thousands of recipients. 

“I started getting phone calls and messages saying, ‘Why did you email me? Why did you email me?’” Gutierrez told Fortune. “My Outlook started...