Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Dear Andre_Wibi,
Thank you for the update, from your provided screenshot it seems your prohibitsendQuota is available and the size of your mailbox is enough. As community team has limited resource to check this issue, we recommend to kindly open ticket with our technical team to trouble shoot this query.
Use this link to route customer to technical support: Contact Microsoft Office Support - MicrosoftSupport.
Thank you for your cooperation and understanding.
For other concerns, please do not hesitate to add you post in the Microsoft Community Team.
I wish you all the best
Sincerely,
Inema Elyse | Microsoft Community Moderator