Losing Business

We have two exchange severs in the Cape Town DC running on IP addresses 196.41.139.16 and 196.41.139.104 about three months back all emails originating from theses servers started to be rejected by the Microsoft free email servers [Email Removed] [Email Removed] etc. the error code is standard SC-001 Please contact your service provider since part of their network icon our block list. Etc. We have performed the necessary tests against our email and DNS servers and all tests report back 100%, we also have no listing on any blacklist server for our domains or IP addresses. We have also used another one of our IP addresses 196.41.139.19 to try to send email as a test, and this was also returned. So therefore the fault is not on our side, the ip range that we are on has been blocked by the free Microsoft servers because of someone abusing an ip address in this range. We are losing customer and request with extreme urgency that this matter be resolved either by getting the range of the black list or by giving us two new IP addresses in a completely new range that is not back listed. ***,***, ***