
As the spam system dealt with the email backlog, it accidentally deleted a tenth of the genuine messages.
"We believe that approximately 10 percent of legitimate email that was de-queued from the new spam appliance to our network was incorrectly recognised as spam and black-holed," Bob Pullen, a member of PlusNet's customer support staff, said on the company's website.
"Additionally, the same percentage of new legitimate mails received between approximately 5pm and 11pm last night have also been deleted."
Pullen said that the messages are not recoverable, and recommended that customers ask people to resend messages wherever possible.
PlusNet apologised for the losses and stressed that the problem had been fixed. "All new email is currently being sent, received and delivered in a timely fashion and customers should no longer be seeing problems," said Pullen.