After composing a new message, provide the recipient’s fax number. WiseFax is a simple to use efax service that allows you to send a fax directly from Outlook to any fax number in the world quickly, easily and securely. How to send fax from Outlook quickly and easily with WiseFax? Insert recipient’s fax number as the email recipient (in the form of for example: Attach files that you wish to fax.