Problem can be solved by
If they select Explorer view, they can either:
1. Right-click a document and choose Send to | Mail Recipient
2. Drag a document into an e-mail message, or
3. Copy and paste the document into a message.
If the recipient has access to the document library, they could use any
other view, right-click the document and choose Copy Shortcut and paste
the URL into the mail message.