Filetype issue

[Lozzano]

Hi,

I have a issue with the attatchment of certain filetypes on OTRS tickets generated through the webinterface.
We can for instance without any issues attatch a .jpg file, but when we try to attatch a .xlsx file the server sends us (the web browser) the index.pl file as a download instead of uploading the file. Which is very strange. After downloading the index.pl file, I can actually go to the ticket in question which then lets me see and also download the file i just uploaded - but the file is not attatched in the email sent to the customer. We have checked that it is not the size of the files, since very small files have the same errors.

So in short: We can upload files, files are also being stored, but only certain filetypes (eg. jpg) are actually being sent as attatchments to the customers.

Does anyone have some insight on what this could be caused by?
The system is running on CentOS linux and is the most recent stable version of OTRS.

Best regards,
André V.