I concur, Nitroid's "Touchdown" works wonderfully. And I cannot say enough about the tech support. In the early versions (which were a bit buggy but still worked well) they staff was responsive and helpful in what turned out to be a very stupid config error on my end. They were willing to help me troubleshoot multiple times (thru e-mail but extremely fast, I have a gmail thread with about 6 or 7 responses in a row in one day). When all was said and done I was left with a "now that's how you handle a frustrated customer!" feeling, in a word, they rock!
P.S Touchdown allows you to choose which folders from your server you wish to see if your like me and don't have everything flooding your inbox. That was a big issue for me on the old work email app from the earlier Hero roms.