I have a ASP.NET web application that sends emails to my companies distribution lists. To prevent spamming the distribution lists have been changed to accept emails from authenticated users only, now the emails are being send and users are notified by with an email containing a message that they do not have permission to send to the distribution list. I have put in the code to logon as my authenticated user, impersonate that user, and send the email (with the credentials of the of my authenticated user. It works on my local machine but when I publish to the server, the emails are not sent (with the same message/ no permission). Is there a way of making to make this work using authentication and impersonation? I have googled and tried different settings, but it is not working for me.