[Exim] rejected recipients

Hi

Any ideas why my exim 3.16 MTA is rejecting email from this address:

2000-08-22 01:36:03 reject all recipients: 3 times bad sender <f1.sasha.co.za@???> H=www.i
nfonetix.co.za (infosrv1.infonetix.co.za) [196.25.201.76]

Thanks!

-- salvo (Salvatore Greco | ICQ 8084066)