You can use the EmailComposeTask to use one of the email accounts on the phone to send you an email. Keep in mind that this method means that the user will get to edit and then possibly not send the email, but it is one of the simplest ways.
Microsoft.Phone.Tasks.EmailComposeTask emailComposeTask = new Microsoft.Phone.Tasks.EmailComposeTask();
emailComposeTask.To = "tomail@localhost.com";
emailComposeTask.Cc = "ccmail@localhost.com";
emailComposeTask.Subject ="Your Subject here";
emailComposeTask.Body = "Your mail content here";
emailComposeTask.Show();
If you are looking to have the user not involved at all then I would suggest a web service online that would take the message you want to send and have it do it using something like ASP.NET like you already mentioned.