This text only shows how to send e-mails in asp.net 2.0, including html emails.
This article do not show how to send emails with attached files. This is a subject for another article.

Follow the steps described below.

1- First, put this configuration int the web.config file in the web application root folder: 

    ...
    </system.web>
    ...
    <system.net>
        <mailSettings>
            <smtp from=" This email address is being protected from spam bots, you need Javascript enabled to view it ">
                <network host="192.168.0.6"
                         port="25"
                         password="pass"
                         userName="userx" />
            </smtp>
        </mailSettings>
    </system.net>
    ...

The following code can be used to send emails.
You must replace the '...' by the appropriated 'using xxx' lines if necessary.

    ...
    using System.Net.Mail;
    ...
    ...  
     
    SmtpClient client = new SmtpClient();
    MailAddress from = new MailAddress(" This email address is being protected from spam bots, you need Javascript enabled to view it ", "namefrom");
    MailAddress to = new MailAddress(" This email address is being protected from spam bots, you need Javascript enabled to view it ", "nameto");
    MailMessage message = new MailMessage(from, to);
    
    message.IsBodyHtml = true;
    message.Subject = "Your friend xxx blablabla..";
    
    string fullText = "this is the full mail text.... lalalla..."; 
    message.Body = fullText;
    
    try
    {
        client.Send(message);
        Response.Redirect("somepage.aspx");
    }
    catch (Exception ex)
    {
        //using some log component, you can remove this lines if you want                               log.Error("Error sending email");
        log.Error(ex);
    }
    

That's it! easy and simple! In the try block, the redirect was only used to send the user to the success page.