Sir, 

I am using Visual Studio 2010, Coding in VB.net

GMAIL Error: The SMTP server requires a secure connection or the client was not authenticated

Following Mudassar's above article I tried to make an email form in asp.net. 

But still I am having same problem. 

I am getting an error like :

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.0 Authentication Required. 

Pl. guide. 

Thanks