Hi Milan, thank you so much for your answer.
I have 2 comments:
1- when I go into /Campaign Management/Deliveries/ I cannot find deleted deliveries
2- also the folder I deleted was on the same level as the "deleted deliveries" folder is shown in the route you mentionned Campaign Management/Deliveries/Deleted deliveries/
I'm attaching what I'm able to see on my folder.
The folder I deleted was one like the named SEASK in the picture.
Inside all of those sub-folders of SEASK are only workflows