Provided that the receiving users have access to the Alfresco repository, it is advised to send a link to the document using "Copy Link address" instead of attaching the document to the email. This avoids the multiplication of identical information in the organization.
You can create links to documents in Fred. Just choose "Copy" from the right-mouse menu opened on a document.
Once copied, you can execute paste in any folder in Fred. Right click on the folder where you want to create a link to the copied document. Choose "Paste as Shortcut". The link will appear.