Postfix non-interactive Install
November 15 2011 17:30 CET
Debian and Ubuntu should be able to handle dpkg installs non-interactively by specifying a variable for DEBIAN_FRONTEND=noninteractive.
However, postfix seems not to respect this and starts whiptail to ask you whether the machine is “an internet site” etc.
The trick is to prepopulate /etc/mailname and /etc/postfix/main.cf
After this you should be able to do this:
DEBIAN_FRONTEND='noninteractive' apt-get install -y -q --force-yes postfix
Live long and prosper :)