Problems with links in PDF

Hi everyone,
I am experiencing some troubles with a document exported in PDF.
I created the file myself including links to web pages. When I open it on my laptop using Adobe Acrobat Reader DC or Anteprima (I am a macOs user), I have no problems. But, when I attach the document to an email, the recipients can click on the links in my documents only when they open the file through the preview feature. When they download it and open it with whatever app, the links are no more visible. How could it be possible? I'd be most grateful to receive insightful comments and tips. Thank you in advance!