Being that this is the SmaterTools community our opinion of the product will be that it is one of the best available for the price.
You should read through the information on the link above and see if it covers the features you are needing. You can also download and install a free version to try it out yourself.
If you have never run/installed a mail server on your own I can assure you it's not a simple task and does involve a lot of work no matter what product you choose.
This community is full of very friendly helpful people that will answer any questions you have.
DXD Technology Solutions, Inc.
PO BOX 2269
Oldsmar, FL 34677-2191