Steps to configure Blackberry:

1)   Sign up with Blackberry.net for an email address, i.e., username@blackberry.net

                  2)   Configure your office email account to auto forward all email to username@blackberry.net

                  3)   Configure Blackberry to check Blackberry.net email

                  4)   Set the Reply-To setting on the blackberry to your office email address

This configures your Blackberry to receive email to the handheld through your Blackberry account. And also configures your handheld to set all outbound email’s replies tback to your main office mailbox.