A heads up.
As of 2/26/14 when running a manual update (sudo aptitude update && sudo aptitude dist-upgrade) on a 0.9.0 iRedMail server running apache on Ubtuntu 14 LTS the nginx package is defaulting to be installed.
If one proceeds with the install apache will show errors on startup and nginx will replace apache (which some probably don't want).
Been testing this program for the last couple of days and although personally prefer apache to nginx (apache 2.4 largely catches up with nginx in many ways in terms of speed and nginx is "freemium") this issue above is probably a good reason why only one web server should be supported by default in iRedMail going forward.