Mail setting cannot work - pls help

I follow the following steps for the google mail server setting and have problem


http://mail.google.com/support/bin/answer.py?answer=13287

Outgoing Mail (SMTP) Server - requires TLS:   
smtp.gmail.com (use authentication)
Use Authentication: Yes
Use STARTTLS: Yes (some clients call this SSL)
Port: 465 or 587

Please advice how can I set the Use Authentication to Yes
in nopcommerce mail setting  ??

In mail settings (Configuration --> Global Settings --> Mail Settings) it has a check box that says use SSL. Check this.

Thks

I had tried that the followings:
port : 465
and
Enable SSL: ckecked (yes)


But got the error below:

Request for the permission of type 'System.Net.Mail.SmtpPermission, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.

Sam

Hmm not really sure.  Is you website running in full trust?  If not sure best to ask your webhost.