VERIFIED SOLUTION i

Portrait Dialogue - How to stop search engines from listing web mail pages

In Portrait Dialogue (PD), search engines may find, and list personal web emails which are made available in customer emails when they click on the "view in Browser" link.  

To stop search engines from finding your your available web pages (e.g. web pages, questionnaires, etc.) you have to create a file named robots.txt in the root directory of web application.  
To block the "mywebapp" directory, it would have to have the following content: 
User-agent: *
Disallow: /mywebapp/

Alternately, to put the whole site off-limits it would include this:
User-agent: *
Disallow: /

You will probably have to wait several days until the indexed files vanish from the google index and then make them public again.

You can read about how it works here http://www.robotstxt.org/ and here https://support.google.com/webmasters/answer/6062596?hl=en&ref_topic=6061961

There seems to be some conflicting advice on the web about where to put this robots.txt file. 
This forum article, http://stackoverflow.com/questions/2984607/where-to-put-robots-txt-file says the file should go deeper (e.g. http://www.mySite.com/MyWebApp/).

But, this page, http://www.robotstxt.org/robotstxt.html indicates that it should go in the root directory of the web site (e.g. http://www.mySite.com/).
To further that argument, the "Disallow" line, or lines, in the robots.txt file are intended to indicate the web pages to ignore.

This page, http://www.robotstxt.org/faq/future.html makes it clear that this is not a standardised mechanism, so there don't seem to be any true all encompassing guidelines.

Therefore, it certainly would not hurt to put a version of the file in both places (http://www.mySite.com/ and http://www.mySite/MyWebApp/).
Best advice is to do what you think will work, and test it to make sure (https://support.google.com/webmasters/answer/6062598).
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ADITIONALLY - from this site - http://www.robotstxt.org/meta.html

About the Robots <META> tag

In a nutshell

You can use a special HTML <META> tag to tell robots not to index the content of a page, and/or not scan it for links to follow.For example:
<html>
<head>
<title>...</title>
<META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW">
</head>

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There are actually only very few of these physical web pages.
The only physical paths refer to the ‘view in browser’ pages and the questionnaires.
(Questionnaires are not in use at ANWB as far as I am aware)

The list of pages requiring changes are

The “MHCwa” web application is installed at ANWB as “campagnekliks”.

· \MHCwa\ClearCache.aspx

· \MHCwa\Default.aspx

· \MHCwa\DefaultAn.aspx

· \MHCwa\ErrorHandlerPage.aspx

· \MHCwa\Login.aspx

· \MHCwa\Msg\Em.aspx

· \MHCwa\Msg\Emt.aspx

· \MHCwa\WebPages\GetFile.aspx

The “MHWu” web application is installed at ANWB as “campagneafbeeldingen”.

· MHWU\ErrorPages\Error.aspx

· MHWU\ErrorPages\Error.htm

· MHWU\ErrorPages\Redirect.aspx

In each file, the following meta tag should be added immediately before the </head> tag near the top of each file

<meta name="robots" content="noindex,nofollow,noarchive">

So, for example, in Em.aspx the result will look like this:
<head id="headTag_directRef" runat="server">
<title>Email Message</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta http-equiv="X-UA-Compatible" content="IE=10,Edge" />
<meta name="robots" content="noindex,nofollow,noarchive">
</head>

 
UPDATED:  April 4, 2017