It is both good and bad that emails are not sent out from the demo environment. For example, it can be difficult to access your guest portal or check-in to test something if you haven't received a real email from the system.
Additionally, it is also a problem to test email templates if you choose to build them yourself because the code (HTML/CSS) generated by MEWS is not 100% consistent with the code you insert.

Therefore, it would be helpful if you could either enable email sending in the demo environment, so you can test the flow 100%, or if there was an option to send a real email from the 'Mail templates' section under 'Guest experience' to ensure that emails that are difficult to trigger (such as 'Automatic settlement failed') also look good on various email platforms. It is a general problem that email platforms interpret HTML/CSS differently, which makes it difficult to trust that the preview MEWS shows is exactly how the email will appear in Gmail, Outlook, Thunderbird, etc.