$ go get github.com/genuinetools/upmail

$ upmail -h
upmail -  Email notification hook for https://github.com/sourcegraph/checkup.
Usage: upmail <command>
Flags:
  --appengine       enable the server for running in Google App Engine (default: false)
  --password        SMTP server password (default: <none>)
  --recipient       recipient for email notifications (default: <none>)
  --mailgun-domain  Mailgun Domain to use for sending email (optional) (default: <none>)
  --sender          SMTP default sender email address for email notifications (default: <none>)
  --server          SMTP server for email notifications (default: <none>)
  --username        SMTP server username (default: <none>)
  --config          config file location (default: checkup.json)
  -d                enable debug logging (default: false)
  --interval        check interval (ex. 5ms, 10s, 1m, 3h) (default: 10m0s)
  --mailgun         Mailgun API Key to use for sending email (optional) (default: <none>)
Commands:
  version  Show the version information.