In response to Vadim Vygonets:
> > and replace /usr/sbin/mailwrapper with a symlink to Exim.
>
> No. Editing /etc/mail/mailer.conf and replacing every instance
> of sendmail with exim is the way to go, and is enough.
I'm sure what I do is unnecessary extra work, it just gives me great
pleasure to disinfect _all_ traces of sendmail off my machine. I also
never know exactly what people might put in their scripts -- a direct
call to mailwrapper would be silly but I am sure someone, somehwere,
has done it.