Why don't you have .NET 3.5 as a selectable framework in IIS

The reason is that the .NET Framework 3.5 delivers not whole new runtime machine, but only library extension of .NET 2.0. In other words there are no new CLR or new language compilers. But there are new available libraries and new versions of C# (3.0) and VB (9)

.NET Framework 2.0 includes the CLR, Winforms, Asp.NET and web services.

.NET Framework 3.0 includes in addition libries for WCF (Windows Communication Foundation), WPF (Windows Presentation Foundation) and Windows Workflow (WF).

.NET Framework 3.0 includes in addition libraries for AJAX, LINQ and REST

Finally you will see there is no problem with your IIS. You've just received some new additional and really good features for easier programming.

Gmail consider the mail as SPAM. How to avoid that?

Obviously Gmail uses Sender-ID and DKIM to verify every email. That is why you need to modify DNS records for your domain using txt record. Here is a tutorial how to do that openspf.org.
You can build your txt records using the wizard and add them. You need something like:
record for domain.com in txt: v=spf1 a mx ~all
record for the mail server mail.domain.com in txt: v=spf1 a -all

Very good way to see how your html table will look like


Interactive tool for creating good looking html table using css. Make the table you want and copy and paste the generated css classes.