Using the standard “send an email” step, a failure to email is an error. It would be nice if there was an option to make this only a warning. On more than one occasion, one of our deployments has succeeded, only get an error, ironically, attempting to sending the “deployment succeeded” email. And then we can’t deploy to the next environment.
Thank you for the suggestion. A feature that would cover this is already on our radar, the details are in this GitHub issue. If you have a view on how you would like that implemented, please leave a comment on that issue. We don’t have a timeline for implementation though.