[Asterisk-Users] FW: Sending voicemail with qmail and call waiting

[Ing Isianto Istiadi]

Dear all,
Is * capable to use qmail as a MTA?
If so, how can I set it?
I'm using asterisk v0.5, and TDM30B (FXS), Wildcard X100P(FXO), and
x-lite(SIP softphone).
In zapata.conf, I put already callwaiting=yes. My PSTN doesn't not support
the callwaiting feature, so I don't expect the FXO is call waiting enabled.
The question is can FXS and SIP support call waiting?? Cause everytime I
called my FXS, it always gave me a busy signal (when the fxs port is in
use).
Thanks

Isianto