SMTP outgoing email servers

smtp.dsl512.co.za    -> IS ADSL
smtp.dial-up.net     -> IS Dialup (56k and ISDN)
smtp.saix.net        -> SAIX ADSL
smtp.iburst.co.za    -> iBurst
mail.mtn.co.za       -> MTN 3G
smtp.vodacom.co.za   -> Vodacom 3G