By having a copy of a external file as attachment instead of only having a link to it, we can take advantage of the great preview functionality.
How ever, having copies of a file increase the risk of having multiple versions and loosing track of the relevant document.
In my case, we have customers who wants to link to files in SharePoint and other dms.
So I'm wondering, how you guys solve this challenge. I'm currently thinking about a simple itemlist having a hyperlink column to store the links to the external content.