Microsoft recognise that RIM (Research In Motion) and their mobile devices are a big part of many modern enterprises so when they ask ”Will it work with my Blackberry?”; the answer is “Of course it will” 
Blackberry Internet Server (BIS) support is part of the standard cost and if you require full integration then Blackberry Enterprise Server (BES) can be added for an additional cost.
Pricing:
Exchange Online costs £6.69 per user per month, so £80.28 per user per year.
Blackberry Support:
Blackberry Internet Server (BIS) support is included in the standard Exchange Online price.
Blackberry Enterprise Server (BES) support is an extra charge as follows:
Initial Setup = £33.47 for a minimum of 20 users so a total fee of £669.4
Ongoing Costs = £3.35 per user per month. This is on top of the Exchange cost thus £6.69 + £3.35, making a total of £10.04 per user per month.
The process is that MS will take on the customer’s Blackberry licences and use those to provide the service from their datacenter on the end user’s behalf. So if you don’t already have the licences, you will need to factor that cost into your budget too.
