Is there any updates that I should be installing on BES 4.1.6 without going to 5.0 that would imporve the communications between BES and Exchange?

I am finding that my emails are being slowly captured by the BES service and forwarded to my BB. Point in hand when updated my BOLD to the latest OS and re-ran EA, the email comes into my inbox and it takes about 30 seconds for the BES server to pick it up and start the sync process with the device.

I am running on a GBit LAN with Dell Precision 490 workstations as servers; my SBS 2008 runs on a dual xeon 3.2Ghz, 16GB RAM, while my BES runs on a dual 2.0Ghz, 4GB ram (windows 2003 server) box.

Thanks
Andrew

Use the BlackBerry Resource Kit and run the messageflow.exe tool against your logs to see if you can recognize any problems.
BES Logs ... What's in them? Part 19 of 20 (MessageFlow.exe BRK Tool) - Port3101.org : Your BES Connection

Also how do I know which release of SP6 I have installed in my BES server?

I have version 4.1.6.9 but I am not sure what MR version that is!?

Okay I looked at your link and went to the 'support info' which says I have version 4.1.6 (bundle 30) installed, which doesn't make any sense to me as it doesn't tell me what MR I have installed!?

Also the link to RIM's site for BES for Exchange only goes up to SP6 just shy of 4.1.6.9 which doesn't help me either! :(

A.

That means you don't have any MRs installed at all. You're running the gold release of SP6.
KB17611 - Bundle versions of the BlackBerry Enterprise Server for Microsoft Exchange - Port3101.org : Your BES Connection

So I need to start with MR1 and go up to MR7 then?

A.

No, you can install the newest one straight away. They're cumulative.