When you are testing templates:
  1. Same email sent repeatedly to same address does not work.  It does not show up in Sent Email.  Presumably this is your anti-spam.  This complicates testing emails.
    1. Suggestion:  Turn off the repeat email detection for user's domain - if I am sending an email repeatedly to someone at my domain this is almost certainly legitimate testing.
  2. Despite the email not going out, you still get the message that sending the email succeeded.  This is just wrong - it did not succeed.