Thanks for your quick reply.
I believe we found a solution for that.
We use Microsoft Office365 but this solution might work if you have a different provider.
What do you need?
Microsoft Account so you can use Microsoft flow
Dropbox account, so you can use the quickfile dropbox integration (More info here)
Go to https://emea.flow.microsoft.com/en-us/
Click “My Flows”,
Click “Create from template”,
Search for “Save Email attachments from Outlook.com to Dropbox” (If you are an office365 customer this is the option you should select)
Make sure you connect to your email and Dropbox accounts and click “continue”
This will create a new flow from template.
On my case I only wanted emails with the subject “Invoice” so I’ve clicked “Edit” on the object “On New email” then “Show advanced options” and typed “Invoice” on to the subject filter.
Just underneath this object, you might see a “+” sign, click it and select “Add Condition”.
In my case I just want PDF files to be saved to the Receipt hub.
“Choose value” select “File Attachment”.
on the condition, object, remove “File Attachment” and add “Name”, ends with “.pdf”.
Drag the object “Create fileScope” to the “Yes” area of your condition.
By default, the file is saved to the “Attachments” folder on your dropbox, but we want to be saved to the Quickfile folder.
Expand, “Create FileScop”,
Expand, “Create File”,
Click “Edit”,
Change the folder path to your quickfile folder.
Rename the flow to an appropriate friendly name, and click “Create flow”.
You are now ready to go, only PDF files coming as an attachment on emails where the subject contains “invoice” will be saved to this folder.
Hope this helps somebody else with the same issue as us. 