I need to find the time and goal of the dynatrace to send a warning message. Where should I find it?
Specifically, the sending time and the target of sending the alarm message.
In the left menu, select Settings -> Integration -> Problem Notification.
You should also become familiar with Alerting -> Alerting Profiles where you can find tune the conditions where alerts are sent out.
If it exists, it would be in the logs, and may require a higher level of logging. However I do not suggest you run with a higher level of logging by default.
Perhaps you can clarify the use case where you require evidence that the email was sent. Some customers send notices to a distribution list, which then they control via their mail system. That way you could include an email accounton that distro list which could be used as an audit trail of all outbound messages.