With the help of several coworkers we are blocking the troublesome User-Agents. Here is a way to do it:
ISAPI Rewrite is a Mod Rewrite implementation for IIS. There is a lite and a full version available here:
http://www.isapirewrite.com/
So with the configuration below you can block the unauthorized blackberries. I will edit the original post to include the solution. For full details see the April 2008 post on the subject on this blog.
RewriteEngine on
#Block Blackberry and other smartphones
RewriteCond %{HTTP:User-Agent} (?:BWC.Worker.*|BWC.Engine.*|MSFT-SPhone.*|PalmOne-TreoAce.*|AvantGO.*) [NC]
RewriteRule .? - [F,L]
#Block Blackberry and other smartphones
RewriteCond %{HTTP:User-Agent} (?:BWC.Worker.*|BWC.Engine.*|MSFT-SPhone.*|PalmOne-TreoAce.*|AvantGO.*) [NC]
RewriteRule .? - [F,L]
Here is another approach for handling the blackberry devices which blocks it by IP address.
http://www.billwarnke.com/index.php/tech/38-internet/54-blocking-blackberry-bis-from-accessing-exchangeowa-email