Error at Activation: Expected to find class "DirectMailTeam\DirectMail\Command\AnalyzeBounceMailCommand" in file "/usr/www/users/wieses/webseite/grassbirdhabitats.test/typo3conf/ext/direct_mail/Classes/Command/AnalyzeBounceMailCommand.php" while importing services from resource "../Classes/*", but it was not found! Check the namespace prefix used with the resource.

[fischhase]

On activation of direct_mail in TYPO3 12 I get error, that the Class AnalyzeBounceMailCommand is not found. It is not a composer installation.
I checked the namespace of the class and the 'autoload' in ext_emconf. Don't know, why autoload fails.