A security breach is understood to have affected several hotel and restaurant Mailchimp accounts.
The four-red-AA-star, 26-bedroom Grove of Narberth hotel in Pembrokeshire was one of the businesses affected. Some guests received an email containing a link to an ‘outstanding invoice' on Wednesday. Within hours the hotel contacted its mailing list warning guests to delete such emails and avoid clicking any links.
The hotel said it was aware of other hotels and restaurants that had been affected and is investigating with Mailchimp as to the source of the breach. It is unclear exactly how many guests or businesses have been affected.
A spokesperson for Mailchimp said: "At Mailchimp, our users' security is our top priority. We have no information indicating the recent use of our platform to distribute these campaigns is due to a compromise of Mailchimp's systems. However, individual accounts are sometimes accessed by unauthorised parties, which can happen when individual user credentials are lost or stolen.
"When we become aware of any unauthorised account access, we notify the account owner and immediately take steps to suspend any further access to the account. We also recommend two-factor authentication and other account security measures for our users as added measures to keep accounts and passwords secure.
"This type of unauthorised access happens on an individual account's end, when a user's password or other credentials are stolen or compromised. This was not a breach on Mailchimp's end."