You should get more specifics regarding BlackBerry Connect, the software which runs on the Nokia E36, allowing it to connect to the BES.
There are limitations that may persuade you to look at a true BlackBerry alternative.
You should also speak with your BlackBerry support person(s) to understand if they can and do support BlackBerry Connect devices such as the E36.
Remember, sales reps are out to sell you service and hardware. In most cases, they tell you something is possible, when in fact it is NOT possible. I know this because several times a week, users explain to me that they "should" be able to do X,Y, or Z because the sales rep said so. I have to explain that we either don't have the necessary policy, proceedure or what-have-you in place to support something.
You had me at EHLO!