There are some absurdities in this question. First of all, is it going on on client side or server side? I think your're talking about client side — if it was a server side, it would be your Web page, how can it contain viruses?
But if this is a client side, you cannot know if it is ASP.NET page or not. From the standpoint of a client, there is not such thing as APS.NET or any other server-side technology (PHP, Python, JPS, whatever…).
Not clear what do you mean by scanning a page with anti-virus. What do you want to scan, a text file? If you download some binaries, they are not called Web pages. And again, despite the popular opinion, it is only possible to get a virus from the Web page because the Web browser does dirty things, for example, loads and execute some binary codes from Internet. Don't do it; and you won't get infected. I don't see how you can get a virus as a result of the post request. The page is already loaded and some scripts are already executed.
Anyway, it's possible to filter out suspect parts of the page right after it's loaded, but it could not be related to post request.
Not clear, what is "fire e-mail". Is your click an anchor with the "mailto:" schema, you can open some e-mail agent — locally. It has nothing to do with sending messages through the Web site. As the Web application knows nothing about client's opportunities to send mails, normally, the mail is sent on the server side. The client performs the HTTP request using "POST" method using the form containing data needed for mailing. The server gets posted data, filters it, makes a e-mail message out of it and sends using its own mail server (such as SMTP). This process could be done in a very secure way, but it needs a lot of care about filtering the data. If the e-mail is made out of client data as is, it can be easily used to turn a server into a zombie distributing spam or something like that. Proper filtering of this data can completely eliminate the possibilities for such exploits. Again, it is related to server-side Web development and has nothing to do with scanning of the Web page for viruses. It's not clear why sending a e-mail can be a special concern at the client side.
[EDIT]
Also, be aware of danger of sending e-mail based on the user input. Please see my recent answer:
unable to send mail , it showing the error in below code .[
^].
—SA
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