This is the official Heroku buildpack for PHP applications modified to run Pear Mail. Additionally, GZIP compression is enabled.
Method 1: In your app setting page include this repository as a BUILDPACK_URL in the Config Vars.
Method 2: In your app directory run the following command:
heroku config:add BUILDPACK_URL=https://github.com/blindstuff/heroku-buildpack-php.git
Copy the snippet above into CLI.