How can I limit a shared link so the receiver can only download the file and not share it?

Hi skillfusion, thanks for messaging the Community.

In general, it wouldn't really be possible to prevent a user to only download the file, since the shared link is just a normal URL for the browser which anyone can access. 

Even if there was a method for them to download the file on its own, there wouldn't be anything you could do to prevent them from sharing the file itself via email or another method to another person.

If you have any further queries, feel free to message back.

skillfusion I'd like to add a bit more color to our sharing capabilities.  You have a couple options with caveats to share so others cannot edit or reshare.  

Preventing File Editing

To prevent recipients from editing, create and share a view only link.  Recipients will only be able to access a web preview of the content and will be able to download from there.

Preventing Re-sharing With Others

Preventing re-sharing requires you to invite recipients as view members directly to the content you're sharing via their email.  This requires recipients to login and have a Dropbox account.  This is how Dropbox verifies only those invited are able to access your content.  You can also further share links with these invited members by creating a view link and setting the link audience to "only those invited".  

Otherwise, Jay's response is 100% correct.  Hope this helps!

You can read more detail in these help center articles: 

1. https://help.dropbox.com/share/share-outside-dropbox
2. https://help.dropbox.com/share/create-and-share-link

Jay, thank you so much for your response.  I appreciate it.  Garry