Yes, it is usually possible to authorize several email addresses to send faxes from your internet fax to email number.  Check each plan to see how many email addresses can be added to the "can send" list; it is usually mentioned in a specific company's review here on the site.  With some providers, it is also possible to authorize an entire domain, which means that you can authorize anyone with a @yourcompany.com email address to send faxes to your number.

When you add an email address as a recipient, a copy of all faxes will be sent to that email address, so make sure this is something you actually intended to do.