Acrobat User Community Forums

You'll need server side tools for this, and there are plenty, as well as many different approaches. 

1. Filling in a existing PDF form.  There are a couple of ways to do this.  The easiest way is to create a PDF data file,  in FDF, XFDF, or XDP(For Live Cycle Forms).  Then point the user to the URL of the data file.  The data file must also contain the URL for PDF form.  When the user clicks on the data file link, Acrobat opens and loads both the form and the data. 

There are also server side form filling tools you can buy from Appligent, ActivePDF and others.  In this case the server script emails the whole form.

2. Create and email a PDF report instead of filling in an existing form.  There are serveral PDF creation tools and libraries out there, from iText (an open source Java PDF Library) to Adobe tools like Flex and ColdFusion, even Crystal Reports has PDF creation.  Just do a google search on PDF Tools and PDF Libraries.  You'll find one for whatever server side technology you're using.

3.  Buy a form data managment service like www.formrouter.com.  There are only a few of these services around, but they'll take care of everything for you.