Send bulk mail in background in asp.net application

No. It is possible in Windows app that way. ASP.Net is a different thing

It is possible in web application.

link : http://www.dotnetfunda.com/articles/article613-background-processes-in-asp-net-web-applications.aspx

If it is possible that why are you creating a windows service

http://www.aspforums.net/Threads/120414/Creating-Windows-service-in-local-system-to-access-db-in-hosted-server/

?

For time being i created windows service.But that is not the solution for it as it is dependent on vps.

The  following link :

http://www.dotnetfunda.com/articles/article613-background-processes-in-asp-net-web-applications.aspx

Using the class mentioned above is it possbile to send  bulk mails? If so ,how?

Well you need to ask this question from the Author of the article. As far as I know the solution would be windows service or an Exe

Simple SMTP E-Mail Sender in C#… Console application