Please run the following URL to check email is working or not:
http://localhost/orangescrum/cron/test_email/?to=emailId (if you are using localhost)
http://127.0.0.1/orangescrum/cron/test_email/?to=emailId (if you are using IP)
http://myprojects.orangescrum.com/cron/test_email/?to=emailId (if you are using any valid domain)
If the email is not working then please follow the installation guide again.
Check gmail security issues here. Please see below links , you have to change some configuration at email end.
Also check app/tmp/logs/os-email.log file for any error.