Here's the situation. 3 different companies run MS SBS (exchange) mail servers and fail to apply Aug 2004 security updates which in effect turns their mail servers into almost open relays. (in effect a cross between an open relay and an autoresponder gone wrong) A client via their own exchange mail server sends out a mailshot to their customers (including the 3 MS SBS servers above) and uses their domain name hosted with us as the From/Reply address. The client screws up the mailshot and sends it out with the list as CC's rather than BCC's When the 3 screwy SBS exchange servers get the mail rather than just deliver locally, they relay mail to all of the CC'd mailing list. As there are 3 faulty servers doing this we get exponential growth in the number of mails being generated, to the point that we have 20,000 emails within 30 mins and 400,000 emails within 6 hours. Most members on the mailing list had their accounts bounce mail for being full so we ended up with a copy of every mail generated by the faulty servers and all of the bounces, autoresponders etc to the point where we had 3 servers working flat out to filter out the mails and try and keep our other customers mail working. After a week of problems we've spent about 15 man hours dealing with the problems. So the question is, given that the administrators of the SBS servers failed to maintain their servers in a fit state while being connected to the public internet would anyone agree that we have a right to claim compensation for negligence on the part of the SBS exchange server owners.