I remember Speedway Now. Russell Lanning took over Speedway Mail at one time too, but he wasn't there very long. I also remember Speedway Mail going the same size as Speedway Star for a while. I think they were trying various ways of increasing the readership.
It was always more difficult to obtain, though, other than at the tracks themselves. I could always find Speedway Star in a newsagent somewhere, but never Speedway Mail. That can't have helped.