Blueyonder, the Internet Service Provider brand of Britain's second largest cable operator, Telewest, announced on Tuesday that it will "step up measures" to deal with spam being sent via poorly-configured SMTP relays on computers connected to the Blueyonder network.

In an announcement email from the ISP's abuse team, customers were informed that if Blueyonder receives more than 300 reports per day to their abuse report email address for a particular IP address, the computer connected to that address will not be able to send email via Blueyonder's SMTP servers until the open SMTP relay on that machine is closed. When a block is applied, an email will be sent to the primary email address of the affected customer's account, with an explanation that they are no longer able to relay mail using Blueyonder's SMTP servers along with some tips to correct the error. A contact phone number will also be provided "for assistance in removing the block once the user has resolved their issues that are resulting in the spam reports."

Affected customers will still be able to access mail via Blueyonder's webmail system. Incoming mail protocols POP and IMAP are not affected.

The full announcement can be found on Blueyonder's help website.