Virgin Media customers were cut off for 4 days with little or no access to their email as the company came under attack by spammers.
According to the Beeb, the spam problem affected a company which processes messages delivered through the Virgin.net platform.
This meant that ten of thousands of Virgin customers had their accounts suspended while the problem was dealt with.
The attack, which was described as "large", began last Tuesday evening, but it took four days for the fault to be cleared confirmed Virgin Media.
Customers are now slowly receiving their emails but the BBC was told that access via webmail may have been taking longer to restore.
Not all Virgin Media clients were affected though - in fact less than half of the 200,000 customers were cut off, but for some, they were faced with an error message whenthey tried to log onto their account.
"Since late Tuesday evening, some customers on our Virgin Media DSL service may have been unable to access e-mail or webmail", a spokesman told the Beeb.
"This was due to a suspected spam attack suffered by our e-mail supplier which also affected a number of other ISPs. No customers on our cable service were affected."
"All customers are able to access e-mail again now, though due to a large queue of undelivered e-mail messages, there may be a short delay before some e-mails reach customers' accounts."