Can't beat that headline. UK ISP Virgin Media is having a few problems with its spam filters, reports the Register. Previously hosting user mailboxes on Google-managed systems, the ISP was forced to bring it back in house after Google stopped selling the service to ISPs. Apparently, hilarity has ensued.
Good news for senders: Instead of blocking mail outright, suspected spam will now be routed to the spam folder. Sounds like ISP users will be able to identify spam and non-spam to the ISP, to help improve the filter over time.
A quick search suggests that @ntlworld.com and @blueyonder.co.uk are probably the relevant Virgin Media email domains affected by this issue. I'll update this post if I learn more.