sent link to user via email

Try this Link

http://www.techrepublic.com/article/sending-e-mail-via-aspnet/5766248[^]

Hi,

There is no straight forward solution for this. you need to use encryption along with some salt. for every day you need to generate one string and that string will be validated from the server side. Even you need to check if the link is from the same ip address or from the different(in case you want to restrict users).

One of the way is,
You can use MD5 along with some salt. First get the current date. and apply MD5 on that after adding salt(some predefined string). Pass this baked encrypted string to the URL for download in the email.

On the server side you already have the current date. you need to do the same process on the server side. get the date, add salt with the date and generate MD5. If both MD5 match then popup for the download, otherwise you can prompt some message.

You also need to consider localization for this methodology. If you will use Server date then this issue will not happen. so best option is to use server date.

Best luck
-Amit

http://stackoverflow.com/questions/12996995/asp-net-simple-mail-to-send-using-c-sharp[^]
http://stackoverflow.com/questions/15181361/sending-email-verification-link-to-activate-profile-c-sharp[^]
http://stackoverflow.com/questions/10719722/asp-net-app-to-send-an-mail-with-a-hyperlink[^]