The mails I deleted suddenly are no longer viseble in my trashbin. What can I do about that?

Hello krisspinhoven,

Thanks for reaching out to Apple Support Communities. We see you have some questions about missing mail on your Mac, and we'd like to help. As you had moved these to your trash folder, there's a chance they could have been removed, as some carrier settings will remove these after a certain time. However, the following link would be the best bet in trying to locate them: If emails appear to be missing in Mail on Mac - Apple Support

Let us know if this helps.

Regards.