Marks & Spencer has warned online customers to expect an increase in spam after hackers stole details from a marketing e-mail provider.
The high-street retailer contacted users on Tuesday night to warn them about the data breach with the following email message:
"We have been informed by Epsilon, a company we use to send emails to our customers, that some M&S customer email addresses have been accessed without authorisation.
"We would like to reassure you that the only information that may have been accessed is your name and email address. No other personal information, such as your account details, has been accessed or is at risk.
"We wanted to bring this to your attention as it is possible that you may receive spam email messages as a result. We apologise for any inconvenience this may cause you. We take your privacy very seriously, and we will continue to work diligently to protect your personal information."
Epsilon is the world's largest distributor of permission-based email, sending more than 40 billion messages a year - and the recent data breach is feared to have been the largest in US corporate history.
The company's 2,500 clients include financial providers Capital One, Chase, CitiGroup and JP Morgan Chase - leading to fears that customer details may be used to launch phishing scams, tricking customers into giving away their bank account or credit card details.
The warning from M&S follows a spate of attacks on marketing email providers. In March, UK music and video retailer Play.com alerted its customers to a data breach at its supplier Silverpop that resulted in email addresses being stolen, but said that no other information had been compromised.