In its first attempt at sending e-mail notifications to scholarship recipients, the University of California at Davis erroneously delivered good news to 6,000 prospective students on Monday, telling them they had each won a prestigious $7,500 merit scholarship. The students were notified three hours later that they had not won the scholarships after all, but that they had been accepted for admission.

The university's chancellor, Larry N. Vanderhoef, sent an e-mail letter of apology to the students late Tuesday. "As the parent of two college-graduate children, I understand the challenging roller-coaster ride our error may have caused you and your parents," he wrote. "I'm very, very sorry for any confusion, frustration, and disappointment that resulted from our mistake."

Several prospective students, parents, and alumni called the university to complain about the mistake and about the university's initial "oops" letter, which did not contain an apology, said Lisa Lapin, a university spokeswoman.

The mistake was made at a university office that handles bulk e-mail messages, said Ms. Lapin. A staff member there was asked to send one letter to the 800 students who had received the university's Regents Scholarship, and a different letter of acceptance to a list of 6,000 students. But the staff member sent the same scholarship letter to both batches of e-mail addresses.

"There's that expression 'To err is human, but to really mess up you need a computer.' That's kind of the case here," said Ms. Lapin.

Ms. Lapin said the 6,000 students still got good news -- that they were among the 53 percent of applicants gaining admission to Davis this year. "They should still be very happy about that," she said. "We're sorry that their admissions acceptance was tainted by the fact that they thought they might have gotten a Regents Scholarship as well."

But not all of the students are happy, and some said they may think twice about accepting the offer of admission.

"Normally you expect colleges to have it together a little bit more," said Zach Baron, one of the students who got the erroneous letter, in an interview with The Sacramento Bee.

Ms. Lapin said the university has already added more checks to its bulk e-mail process.

The university made a similar mistake two years ago, when the admissions office erroneously sent acceptance letters through the mail to about 100 international students who had actually been rejected. The university quickly sent the applicants e-mail messages apologizing for the error.