Vodacom, WHY are my mails logged as spam?

I have an Mweb account and a Vodacom(n) data bundle of 5 gigs. Recently my mail has been returned by smtp4.vodamail.internal [mailto:***rnal] as being "Spam" and - get this - "but for less obvious cases some balance between losing genuine mail and sending undesired backscatter is sought, and there can be some collateral damage on either side." Get this, Vodacon, this "undesired" blocking is causing massive problems with me. How cute about the "undesired backscatter". How DARE you decide what is spam and what is not. I don't spam. I'm paying you to block my mails? Please fix this juvenile behaviour as soon as you read this? I have contacted Mweb and the say my account is clean. Vodacom is blocking it. Please, I have tried to send mails to you, phone your call centre, but I get no meaningful response. Thanks, Bruce.