[foreman-installer] Failing to install on ubuntu 14.04 -- email_delivery_method

Hi there,

I've been trying to use foreman-installer to install foreman, and keep on
hitting this strange error:

"[ERROR 2015-09-13 15:55:22 main] Evaluation Error: Error while evaluating
a Function Call, email_delivery_method can be either sendmail or smtp, not
foreman::params::email_delivery_method at
/usr/share/foreman-installer/modules/foreman/manifests/init.pp:289:5 on
node jamespc.local"

Attached are foreman-installer.log and foreman-installer-answers.yaml

http://pastebin.com/E2ezQDmX
http://pastebin.com/ar8qs9h4

Any help is appreciated
Thanks
James