Error using webclient with gmail

This is the code:

response =
    Encoding.UTF8.GetString(
       objClient.DownloadData("https://mail.google.com/mail/feed开发者_Python百科/atom")
    );

And this is the error (exception) I get: WebClient does not support current i/o operation

what could be the reason for that exception?

I believe the error you're talking about is "WebClient does not support *con*current I/O operations".

This exception is caused when you try to make multiple requests at the same time from a single WebClient instance. If you want to make concurrent requests, create a new WebClient instance.