Can't email Hotmail accounts from my Yahoo account - Why?

Every time I send an email to a friend with a hotmail account it I get this error message:


Remote host said: 550 SC-001 Mail rejected by Windows Live Hotmail for policy reasons. Reasons for rejection may be related to content with spam-like characteristics or IP/domain reputation problems. If you are not an email/network admin please contact your E-mail/Internet





This happens whether I email to an individual or to several people - the hotmail addresses all reject my email.





Is there something I can do (adjust settings somewhere) on my end to fix this?
Can't email Hotmail accounts from my Yahoo account - Why?
Happening to me as well. A Google search shows it happens quite a bit - MS Hotmail blocking GMail, Yahoo and others. Someone suggested it was because there might be a dash ( - ) or equals sign ( = ) in the mail sent, which is often related to spam. I checked the mail that was rejected and, sure 'nuff, I had put a dash in it. I may try again to see if it will go through, or if my IP is permanently blocked. They sure make it sound bad, like I was guilty of sending spam or something - which was not the case
Reply:when sending from yahoo, exact same problem here. everything comes back from hotmail and msn
Reply:I don't have the answer, but I have the same problem!!!!


Please someone tell me what to do?!?!?!?!?