(CNN)The Mayo Clinic Alix School of Medicine sent 364 letters of acceptance in error Thursday to students looking for admission.
"Soon after the emails were sent, a technical error was discovered and the letters of acceptance were withdrawn by email," according to a statement on the Minnesota-based school's website.
About three hours after the admissions letter was sent in error, Admissions Dean Dr. J. Michael Bostwick told CNN, applicants were contacted by phone to let them know what had happened.
Bostwick said the school makes offers to just 46 students. Initial offers are always over the phone, Bostwick said.
"It's awful," he said. "We're still not clear how this happened and we're so upset for these folks."
A vendor's glitch sent the letter to everyone who interviewed, Bostwick said.
"We deeply regret having caused disappointment and stress to these applicants, and we are continuing to investigate the issue," the school's apology on its website read.
Frustrated and indifferent students took to a forum on The Student Doctor Network, a nonprofit service for medical professionals, to voice their opinion on the mishap.
"Just sent them an email withdrawing my application," one user wrote. "I know not everyone is in a position to do that, but if you do have options, I'd think about what this whole mess says about Mayo's treatment of their applicants and students."
Another poster suggested students give the school the benefit of the doubt.
"Unpopular opinion time: I don't think it's fair to drastically change your opinion of the school based on this incident," the poster wrote. "Suggesting that this mistake means you would be treated poorly as a student does not make sense."
The Mayo Clinic Alix School of Medicine is ranked ninth in the nation for research, according to US News & World Report.