| | There is another way....
If you are using Outlook or some mail reader software on your desktop at work, then you can set your Outlook to DELETE the messages from your mail server. When you have Outlook open and running at your office, it will download and delete messages from your mail. Set Outlook check for mail like every 2-3 mins or less.
When you leave your desktop, close Outlook, and your mail will be there for your BB to get.
Now, with this solution, there is the odd chance that every now and then you will receive the odd e-mail to your BB when it might coincidentally check for mail at the same time as Outlook.