How do I email errors logged with NLog?

Change your encoding from UTF8 to UTF-8.

Assuming there are no other errors in your SMTP settings (which is usually the cause of messages not being sent), it should work.

I think you need to setup the mailSettings in the system.net. Something like this:

<system.net>
  <mailSettings>

    <smtp from="[email protected]">
      <network host="server.net" userName="[email protected]" password="somepassword"/>
    </smtp>

    <!--Just an example for testing. Can't have both-->
    <smtp deliveryMethod="SpecifiedPickupDirectory" from="[email protected]">
      <network host="localhost"/>
      <specifiedPickupDirectory pickupDirectoryLocation="d:\tmp\email"/>
    </smtp>

  </mailSettings>
</system.net>

First option is for using the SMTP server and second to deliver email to your local folder. Second option is good for testing.