bwapp: User not successfully created! An e-mail could not be sent [migrated]

I am wanting to learn with bwapp and I keep trying to create a new user. I have tried two different emails already and I continue to get an error saying unable to do so. I get the following error:

User not successfully created! An e-mail could not be sent…

Any known issues with the bwapp website? Aside from those deliberately baked in, obviously.