unaccurate documentation about default mta

[Johan Boule]

On the page https://help.ubuntu.com/8.04/installation-guide/amd64/mail-setup.html it is said that exim is likely to be installed as the default mta, but this contradicts the page https://help.ubuntu.com/8.04/serverguide/C/postfix.html

As an example, my hardy system ends up having postfix installed rather than exim, although i don't remember having done anything to choose postfix instead of exim. The package is not marked as having been automatically installed. I don't know if there would be a way for me to see what "triggered" postfix to be installed, or if it was installed since the base system installation.

If i understand correctly, exim is becoming the default mta on ubuntu, just like it is on debian. I guess the question is when this default has been correctly applied to all package dependencies. Can we conclude that hardy packages are messy/boggus regarding dependencies on a default mta? If that's the case could it just be documented that's there's no really clear default mta, that it may be either exim4 or postfix, and provide pointers to configure either.