A note about mail.local :

This program is used by the answering machine to let the callee a mail.

It is supplied in case you don't have sendmail nor qmail.
It is used by the default system-wide configuration file, so that ktalkd works
for anybody.

If this program doesn't compile, or if you don't want to install it, 
or also if you want to receive the mail on another machine,
just edit the config file (ktalkdrc if KDE installed, otherwise talkd.conf)
so that MailProg is set to either sendmail or qmail (in sendmail mode).