Emails not being sent

I installed awesome support and it seems all to work, except for emails being sent out. Neither the user nor the support staff receives any email when tickets are created or updated. I setup mailgun and added the api key, but still no difference. The checkboxes for the emails to be sent out are also selected.

Any idea why these emials aren’t sent out?

https://www.ads-software.com/plugins/awesome-support/