As part of Business Productivity Online Services (BPOS) implementation for one of our clients in India we were moving their mail boxes from Google apps to BPOS exchange. As part of this move we also had to configure Blackberry email support for them. Our client was using Blackberry support from BSNL and we configured BPOS exchange with the below steps
1. Visit http://bsnl.blackberry.com
2. Login with a valid user name and password. If you don’t have an account create one.
3. Click on Email Accounts from Services category on the left menu
4. Click on Setup Email button
5. In the email setup screen enter BPOS exchange email account and click Next
6. The page will display an error message and ask you to provide additional details

7. Click provide additional settings link
8. In the additional settings page select Microsoft Exchange option
9. Enter your email address, password for the respective fields
10. For the web access URL specify https://red003.mail.apac.microsoftonline.com/owa
11. Enter BPOS user name for the user name field
12. Leave Mail box name field blank and click Next button

13. In the confirmation screen click Finish