Do you know if it's possible to buy tickets for the tazara rail from mbeya - dar - mbeya from Malawi? How much are they and is mbeya the nearest point to get it from malawi?
I don't think it's possible based on what I've read on the internet however if you travel to one of the towns on the rail line then you shouldn't have a problem. Here's a link listing the schedules. Good luck.