I was recently trying to connect to an Exchange server. I got mostly there, then I was told that my phone didn't support the security method required - blast!
I searched around the web a bit and found this to be a common problem.
Like a grizzly old prospector, I finally found that speck of gold at the bottom of the pan - and it's called Touchdown from Nitrodesk.
I installed the free version (30 day trial) to ensure it worked. If you have the required information; it is extremely easy to set up. Once I had it working, I upgraded to the paid version. It's a little pricey when you compare it to other Android apps, but it is a fully-featured product, not just a simple one-function tool.
Highly recommended!
