No warning when deleting an answer if your email server isn't configured

Steps to reproduce:

1. Don't configure your email smtp settings in the Administration
2. Create a new forum with a topic and an answer
3. Delete the answer

You should get some kind of warning that your email settings aren't set and a link to return to the topic, but instead after deleting an answer you just see the "Conversation deleted" text and you remain on the topic page.