Package 'postfix-policyd-spf-python' has no installation candidate

[twinvega]

apt-get install -qq -y postfix postgrey postfix-policyd-spf-python will fail for postfix & postgrey since postfix-policyd-spf-python does not exist.

This breaks the mail server section, can be fixed by installing postfix manually like so:
apt-get install -qq -y postfix postgrey
but the python spf part is left out, so a longer term solution is needed.