Content Type & Metadata retained in a files coming from a different site collection or tenant

[AlbertSP]

Hi,
We noticed that files coming as email attachments from different site collections or tenants retain content type and metadata. When users save the file to a local SharePoint Library it auto assigns a content type (since the source CT doesn't exist in their library). Is there a method to prevent this from happening? We are not interested in enabling a Content Hub, only saving the document as-is and applying our existing content type and metadata. 

[#2]

@AlbertSP 
This is unfortunately expected behaviour. The "files" are probably Office file formats such as docx, xlsx, pptx etc..
The "files" contain the CT and metadata details from the source in the file itself. When such a file is uploaded to a different site the property promotion kicks in and tries to extract the metadata from the file and capture that into SharePoint columns in the target destination.
Alternatives: not really viable I am afraid.
- after downloading open the files in the client App (e.g. Word) and remove the properties
- disabling property promotion (this may not work on SharePoint Online)
- use Power Automate in your target system to erase metadata
I am not aware of tools that can strip metadata from Office files during uploading/downloading.
Paul | SLIM Applications

[#3]

@Paul_HK_de_Jong 

Correct, those are MS office files.
Thank you for your suggestions