The Yankees say an employee sent an email to several hundred season-ticket holders Monday and mistakenly attached an internal spreadsheet that contained names, addresses, phone numbers, fax numbers and email addresses for about 17,000 holders of partial and full-season ticket plans.

The leak was first reported by Deadspin.com.

The team said Wednesday that no other personal or financial information, such as social security numbers, credit card data or banking records, was included in the document.

Premium account holders, such as celebrities, were not affected.

The Yankees say they immediately took measures to make sure a similar mistake won’t happen again.

The team says the letter will be posted on its website as well. The letter says the Yankees ”deeply regret this incident, and any inconvenience that it might cause.”

”A mistake was made. We are being as transparent as possible and have already taken measures and steps to ensure this never happens again,” team spokesman Jason Zillo said.

-AP