Alert to mail in journeys/ Alert Composer don't send

Summary:

Content (please ensure you mask any confidential information):

Hi all,

I defined an alert in a task, the Task Assigned for Performer look like this (with my mail)

although the alert composer history says the alert sent

I don't receive any mails.

I would love to know if you have any idea why.

Thank you

Version (include the version you are using, if applicable):

23D

Code Snippet (add any code snippets that support your topic, if applicable):