Once you get exchange installed, and you have the OWA portion working, you want to make customer access easy. One way is to provide a single URL to go directly to the web folders without users having to type that extra folder path. Here is a simple and easy way to implement that feature without changing IIS with 20 redirections.
Create a simple HTML default.htm page and place the following code in it (this will make the page automatically redirect to your owa folder):
<!DOCTYPE HTML PUBLIC "-//W3C/DTD HTML 4.0 Transitional//EN">
<meta http-equiv="REFRESH" content="0;url=http://[OUTSIDE URL HERE]/owa">
Name the file "default.htm" and place it in IIS's "Default Website" folder.
Now, go to IIS and set the default page as the landing page. From IIS select "Default Document" make sure your on the "Default Website" (see image):
Now, move the default.htm document to the top of the list. (see image).
That's it, short and "SWEET"
Backstory; I had done this technique on an Exchange 2010 email server years ago. I'm currently in the process of updating to Exchange 2013, and I absolutly love this way to redirect. I didn't immediatly look at how the old one was setup and started searching the internet. I found a solution on a forum where someone had asked this question, the response to her was so complicated, they had her redirecting every virtual folder in IIS (Default and Exchange Backend). It was at that point that I looked at my old server. I knew it wasn't that complicated.
I knew at that moment I had to post to my blog the solution. I felt really sorry for her going through all that work, and maybe this will save someone else all that work too. - Thanks for reading.